From b31ab650b730b9179981629fbc55f9050c277463 Mon Sep 17 00:00:00 2001
From: Mike Blumenkrantz <zmike@osg.samsung.com>
Date: Thu, 7 May 2015 14:10:29 -0500
Subject: [PATCH] servo: Merge #5955 - Embedding rebase rage (from
 zmike:embedding-REBASE_RAGE); r=larsbergstrom

This updates all the CEF interface stuff to the current CEF codebase.

Source-Repo: https://github.com/servo/servo
Source-Revision: 92f46e3149df7de59aa5aa6700c1878958e2f273

--HG--
rename : servo/ports/cef/interfaces/cef_url.rs => servo/ports/cef/interfaces/cef_parser.rs
---
 servo/ports/cef/README.md                     |   10 +-
 servo/ports/cef/cookie.rs                     |    7 +-
 servo/ports/cef/interfaces/cef_app.rs         |   41 +-
 .../ports/cef/interfaces/cef_auth_callback.rs |   32 +-
 servo/ports/cef/interfaces/cef_browser.rs     |  557 +++++--
 .../interfaces/cef_browser_process_handler.rs |   38 +-
 servo/ports/cef/interfaces/cef_callback.rs    |   58 +-
 servo/ports/cef/interfaces/cef_client.rs      |   89 +-
 .../ports/cef/interfaces/cef_command_line.rs  |   86 +-
 .../interfaces/cef_context_menu_handler.rs    |  138 +-
 servo/ports/cef/interfaces/cef_cookie.rs      |  527 +++++--
 .../cef/interfaces/cef_dialog_handler.rs      |  120 +-
 .../cef/interfaces/cef_display_handler.rs     |   66 +-
 servo/ports/cef/interfaces/cef_dom.rs         |  232 +--
 .../cef/interfaces/cef_download_handler.rs    |  126 +-
 .../ports/cef/interfaces/cef_download_item.rs |   97 +-
 servo/ports/cef/interfaces/cef_drag_data.rs   |   92 +-
 .../ports/cef/interfaces/cef_drag_handler.rs  |   29 +-
 .../ports/cef/interfaces/cef_find_handler.rs  |  212 +++
 .../ports/cef/interfaces/cef_focus_handler.rs |   35 +-
 servo/ports/cef/interfaces/cef_frame.rs       |   98 +-
 servo/ports/cef/interfaces/cef_geolocation.rs |   29 +-
 .../cef/interfaces/cef_geolocation_handler.rs |   58 +-
 .../cef/interfaces/cef_jsdialog_handler.rs    |   64 +-
 .../cef/interfaces/cef_keyboard_handler.rs    |   32 +-
 .../cef/interfaces/cef_life_span_handler.rs   |  107 +-
 .../ports/cef/interfaces/cef_load_handler.rs  |   38 +-
 servo/ports/cef/interfaces/cef_menu_model.rs  |  173 ++-
 .../cef/interfaces/cef_navigation_entry.rs    |  404 +++++
 .../cef/interfaces/cef_origin_whitelist.rs    |    3 +-
 .../interfaces/{cef_url.rs => cef_parser.rs}  |    3 +-
 servo/ports/cef/interfaces/cef_path_util.rs   |    3 +-
 .../ports/cef/interfaces/cef_print_handler.rs |   93 +-
 .../cef/interfaces/cef_print_settings.rs      |   95 +-
 .../cef/interfaces/cef_process_message.rs     |   41 +-
 .../ports/cef/interfaces/cef_process_util.rs  |    3 +-
 .../cef/interfaces/cef_render_handler.rs      |  133 +-
 .../interfaces/cef_render_process_handler.rs  |   59 +-
 servo/ports/cef/interfaces/cef_request.rs     |  186 ++-
 .../cef/interfaces/cef_request_context.rs     |  272 +++-
 .../interfaces/cef_request_context_handler.rs |   47 +-
 .../cef/interfaces/cef_request_handler.rs     |  542 +++----
 .../interfaces/cef_resource_bundle_handler.rs |   32 +-
 .../cef/interfaces/cef_resource_handler.rs    |   44 +-
 servo/ports/cef/interfaces/cef_response.rs    |   56 +-
 servo/ports/cef/interfaces/cef_scheme.rs      |   55 +-
 servo/ports/cef/interfaces/cef_ssl_info.rs    |  655 +++++++++
 servo/ports/cef/interfaces/cef_stream.rs      |  155 +-
 .../cef/interfaces/cef_string_visitor.rs      |   29 +-
 servo/ports/cef/interfaces/cef_task.rs        |   67 +-
 servo/ports/cef/interfaces/cef_trace.rs       |   29 +-
 servo/ports/cef/interfaces/cef_urlrequest.rs  |  105 +-
 servo/ports/cef/interfaces/cef_v8.rs          |  421 ++++--
 servo/ports/cef/interfaces/cef_values.rs      | 1296 +++++++++++++++--
 servo/ports/cef/interfaces/cef_web_plugin.rs  |   90 +-
 servo/ports/cef/interfaces/cef_xml_reader.rs  |  113 +-
 servo/ports/cef/interfaces/cef_zip_reader.rs  |   66 +-
 servo/ports/cef/interfaces/mod.rs             |  166 +--
 servo/ports/cef/lib.rs                        |    2 +-
 servo/ports/cef/macros.rs                     |    2 +-
 servo/ports/cef/regen_interface_mod_rs.sh     |   45 +
 servo/ports/cef/request_context.rs            |    8 +-
 servo/ports/cef/types.rs                      |  467 +++++-
 servo/ports/cef/urlrequest.rs                 |    5 +-
 servo/ports/cef/values.rs                     |    3 +-
 servo/ports/cef/window.rs                     |   34 +-
 servo/ports/cef/wrappers.rs                   |   39 +-
 67 files changed, 6861 insertions(+), 2198 deletions(-)
 create mode 100644 servo/ports/cef/interfaces/cef_find_handler.rs
 create mode 100644 servo/ports/cef/interfaces/cef_navigation_entry.rs
 rename servo/ports/cef/interfaces/{cef_url.rs => cef_parser.rs} (96%)
 create mode 100644 servo/ports/cef/interfaces/cef_ssl_info.rs
 create mode 100755 servo/ports/cef/regen_interface_mod_rs.sh

diff --git a/servo/ports/cef/README.md b/servo/ports/cef/README.md
index 1832ffef7811..fe3057855dc8 100644
--- a/servo/ports/cef/README.md
+++ b/servo/ports/cef/README.md
@@ -10,12 +10,6 @@ How to test:
 
 Notes:
 * Running with the Debug build in GDB is EXTREMELY slow on startup. Only use this if you are actively debugging an unimplemented CEF interaction.
-* The contents of `interfaces/`, with the exception of `interfaces/mod.rs` is autogenerated. To
-  regenerate:
-    - Check out the `servo` branch of the following repository:
-      https://github.com/pcwalton/chromium-embedded-framework
-    - Change to the `tools` directory and run `./translator.sh`
-    - Run the following command to copy in the Rust header files, replacing `${SERVO_SRC}` with
-      the path to your Servo checkout:
-      $ cp ../libcef_dll/rust/*.rs ${SERVO_SRC}/ports/cef/interfaces/
+* The contents of `interfaces/` are entirely autogenerated. To
+  regenerate, see https://github.com/zmike/cef-rebase/blob/master/README.md for full instructions
 
diff --git a/servo/ports/cef/cookie.rs b/servo/ports/cef/cookie.rs
index 34aae98b594e..a710b70833ca 100644
--- a/servo/ports/cef/cookie.rs
+++ b/servo/ports/cef/cookie.rs
@@ -2,15 +2,16 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use interfaces::cef_cookie_manager_t;
+use interfaces::{cef_completion_callback_t, cef_cookie_manager_t};
 use types::cef_string_t;
 
 use libc::c_int;
 
 cef_stub_static_method_impls! {
-    fn cef_cookie_manager_get_global_manager() -> *mut cef_cookie_manager_t
+    fn cef_cookie_manager_get_global_manager(callback: *mut cef_completion_callback_t) -> *mut cef_cookie_manager_t
     fn cef_cookie_manager_create_manager(path: *const cef_string_t,
-                                         persist_session_cookies: c_int)
+                                         persist_session_cookies: c_int,
+                                         callback: *mut cef_completion_callback_t)
                                          -> *mut cef_cookie_manager_t
 }
 
diff --git a/servo/ports/cef/interfaces/cef_app.rs b/servo/ports/cef/interfaces/cef_app.rs
index 0c22ddc8bc3a..bdd74b11ae80 100644
--- a/servo/ports/cef/interfaces/cef_app.rs
+++ b/servo/ports/cef/interfaces/cef_app.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -106,13 +107,13 @@ pub struct _cef_app_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_app_t = _cef_app_t;
 
@@ -128,7 +129,8 @@ pub struct CefApp {
 impl Clone for CefApp {
   fn clone(&self) -> CefApp{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefApp {
@@ -141,7 +143,8 @@ impl Clone for CefApp {
 impl Drop for CefApp {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -156,7 +159,8 @@ impl CefApp {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_app_t) -> CefApp {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefApp {
@@ -170,7 +174,8 @@ impl CefApp {
 
   pub fn c_object_addrefed(&self) -> *mut cef_app_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -178,10 +183,10 @@ impl CefApp {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -197,7 +202,8 @@ impl CefApp {
   //
   pub fn on_before_command_line_processing(&self, process_type: &[u16],
       command_line: interfaces::CefCommandLine) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -217,7 +223,8 @@ impl CefApp {
   //
   pub fn on_register_custom_schemes(&self,
       registrar: interfaces::CefSchemeRegistrar) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -236,7 +243,8 @@ impl CefApp {
   //
   pub fn get_resource_bundle_handler(
       &self) -> interfaces::CefResourceBundleHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -252,7 +260,8 @@ impl CefApp {
   //
   pub fn get_browser_process_handler(
       &self) -> interfaces::CefBrowserProcessHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -268,7 +277,8 @@ impl CefApp {
   //
   pub fn get_render_process_handler(
       &self) -> interfaces::CefRenderProcessHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -295,7 +305,8 @@ impl CefWrap<*mut cef_app_t> for Option<CefApp> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_app_t) -> Option<CefApp> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefApp::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_auth_callback.rs b/servo/ports/cef/interfaces/cef_auth_callback.rs
index 076346dd8999..f93fb47956f1 100644
--- a/servo/ports/cef/interfaces/cef_auth_callback.rs
+++ b/servo/ports/cef/interfaces/cef_auth_callback.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -71,13 +72,13 @@ pub struct _cef_auth_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_auth_callback_t = _cef_auth_callback_t;
 
@@ -93,7 +94,8 @@ pub struct CefAuthCallback {
 impl Clone for CefAuthCallback {
   fn clone(&self) -> CefAuthCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefAuthCallback {
@@ -106,7 +108,8 @@ impl Clone for CefAuthCallback {
 impl Drop for CefAuthCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -121,7 +124,8 @@ impl CefAuthCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_auth_callback_t) -> CefAuthCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefAuthCallback {
@@ -135,7 +139,8 @@ impl CefAuthCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_auth_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -143,17 +148,18 @@ impl CefAuthCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Continue the authentication request.
   //
   pub fn cont(&self, username: &[u16], password: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -169,7 +175,8 @@ impl CefAuthCallback {
   // Cancel the authentication request.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -196,7 +203,8 @@ impl CefWrap<*mut cef_auth_callback_t> for Option<CefAuthCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_auth_callback_t) -> Option<CefAuthCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefAuthCallback::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_browser.rs b/servo/ports/cef/interfaces/cef_browser.rs
index 474d855ffea2..46c9fcaf1009 100644
--- a/servo/ports/cef/interfaces/cef_browser.rs
+++ b/servo/ports/cef/interfaces/cef_browser.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -186,13 +187,13 @@ pub struct _cef_browser_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_browser_t = _cef_browser_t;
 
@@ -210,7 +211,8 @@ pub struct CefBrowser {
 impl Clone for CefBrowser {
   fn clone(&self) -> CefBrowser{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBrowser {
@@ -223,7 +225,8 @@ impl Clone for CefBrowser {
 impl Drop for CefBrowser {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -238,7 +241,8 @@ impl CefBrowser {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_browser_t) -> CefBrowser {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBrowser {
@@ -252,7 +256,8 @@ impl CefBrowser {
 
   pub fn c_object_addrefed(&self) -> *mut cef_browser_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -260,10 +265,10 @@ impl CefBrowser {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -271,7 +276,8 @@ impl CefBrowser {
   // browser process.
   //
   pub fn get_host(&self) -> interfaces::CefBrowserHost {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -285,7 +291,8 @@ impl CefBrowser {
   // Returns true (1) if the browser can navigate backwards.
   //
   pub fn can_go_back(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -299,7 +306,8 @@ impl CefBrowser {
   // Navigate backwards.
   //
   pub fn go_back(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -313,7 +321,8 @@ impl CefBrowser {
   // Returns true (1) if the browser can navigate forwards.
   //
   pub fn can_go_forward(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -327,7 +336,8 @@ impl CefBrowser {
   // Navigate forwards.
   //
   pub fn go_forward(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -341,7 +351,8 @@ impl CefBrowser {
   // Returns true (1) if the browser is currently loading.
   //
   pub fn is_loading(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -355,7 +366,8 @@ impl CefBrowser {
   // Reload the current page.
   //
   pub fn reload(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -369,7 +381,8 @@ impl CefBrowser {
   // Reload the current page ignoring any cached data.
   //
   pub fn reload_ignore_cache(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -383,7 +396,8 @@ impl CefBrowser {
   // Stop loading the page.
   //
   pub fn stop_load(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -397,7 +411,8 @@ impl CefBrowser {
   // Returns the globally unique identifier for this browser.
   //
   pub fn get_identifier(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -412,7 +427,8 @@ impl CefBrowser {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefBrowser) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -427,7 +443,8 @@ impl CefBrowser {
   // Returns true (1) if the window is a popup window.
   //
   pub fn is_popup(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -441,7 +458,8 @@ impl CefBrowser {
   // Returns true (1) if a document has been loaded in the browser.
   //
   pub fn has_document(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -455,7 +473,8 @@ impl CefBrowser {
   // Returns the main (top-level) frame for the browser window.
   //
   pub fn get_main_frame(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -469,7 +488,8 @@ impl CefBrowser {
   // Returns the focused frame for the browser window.
   //
   pub fn get_focused_frame(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -483,7 +503,8 @@ impl CefBrowser {
   // Returns the frame with the specified identifier, or NULL if not found.
   //
   pub fn get_frame_byident(&self, identifier: i64) -> interfaces::CefFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -498,7 +519,8 @@ impl CefBrowser {
   // Returns the frame with the specified name, or NULL if not found.
   //
   pub fn get_frame(&self, name: &[u16]) -> interfaces::CefFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -513,7 +535,8 @@ impl CefBrowser {
   // Returns the number of frames that currently exist.
   //
   pub fn get_frame_count(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -528,7 +551,8 @@ impl CefBrowser {
   //
   pub fn get_frame_identifiers(&self, identifiers_count: *mut libc::size_t,
       identifiers: *mut i64) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -544,7 +568,8 @@ impl CefBrowser {
   // Returns the names of all existing frames.
   //
   pub fn get_frame_names(&self, names: Vec<String>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -561,7 +586,8 @@ impl CefBrowser {
   //
   pub fn send_process_message(&self, target_process: interfaces::CefProcessId,
       message: interfaces::CefProcessMessage) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -590,7 +616,8 @@ impl CefWrap<*mut cef_browser_t> for Option<CefBrowser> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_browser_t) -> Option<CefBrowser> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefBrowser::from_c_object_addref(c_object))
@@ -611,25 +638,27 @@ pub struct _cef_run_file_dialog_callback_t {
   pub base: types::cef_base_t,
 
   //
-  // Called asynchronously after the file dialog is dismissed. If the selection
-  // was successful |file_paths| will be a single value or a list of values
-  // depending on the dialog mode. If the selection was cancelled |file_paths|
-  // will be NULL.
+  // Called asynchronously after the file dialog is dismissed.
+  // |selected_accept_filter| is the 0-based index of the value selected from
+  // the accept filters array passed to cef_browser_host_t::RunFileDialog.
+  // |file_paths| will be a single value or a list of values depending on the
+  // dialog mode. If the selection was cancelled |file_paths| will be NULL.
   //
-  pub cont: Option<extern "C" fn(this: *mut cef_run_file_dialog_callback_t,
-      browser_host: *mut interfaces::cef_browser_host_t,
+  pub on_file_dialog_dismissed: Option<extern "C" fn(
+      this: *mut cef_run_file_dialog_callback_t,
+      selected_accept_filter: libc::c_int,
       file_paths: types::cef_string_list_t) -> ()>,
 
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_run_file_dialog_callback_t = _cef_run_file_dialog_callback_t;
 
@@ -645,7 +674,8 @@ pub struct CefRunFileDialogCallback {
 impl Clone for CefRunFileDialogCallback {
   fn clone(&self) -> CefRunFileDialogCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRunFileDialogCallback {
@@ -658,7 +688,8 @@ impl Clone for CefRunFileDialogCallback {
 impl Drop for CefRunFileDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -673,7 +704,8 @@ impl CefRunFileDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_run_file_dialog_callback_t) -> CefRunFileDialogCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRunFileDialogCallback {
@@ -687,7 +719,8 @@ impl CefRunFileDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_run_file_dialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -695,28 +728,30 @@ impl CefRunFileDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Called asynchronously after the file dialog is dismissed. If the selection
-  // was successful |file_paths| will be a single value or a list of values
-  // depending on the dialog mode. If the selection was cancelled |file_paths|
-  // will be NULL.
+  // Called asynchronously after the file dialog is dismissed.
+  // |selected_accept_filter| is the 0-based index of the value selected from
+  // the accept filters array passed to cef_browser_host_t::RunFileDialog.
+  // |file_paths| will be a single value or a list of values depending on the
+  // dialog mode. If the selection was cancelled |file_paths| will be NULL.
   //
-  pub fn cont(&self, browser_host: interfaces::CefBrowserHost,
+  pub fn on_file_dialog_dismissed(&self, selected_accept_filter: libc::c_int,
       file_paths: Vec<String>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
       CefWrap::to_rust(
-        ((*self.c_object).cont.unwrap())(
+        ((*self.c_object).on_file_dialog_dismissed.unwrap())(
           self.c_object,
-          CefWrap::to_c(browser_host),
+          CefWrap::to_c(selected_accept_filter),
           CefWrap::to_c(file_paths)))
     }
   }
@@ -738,7 +773,8 @@ impl CefWrap<*mut cef_run_file_dialog_callback_t> for Option<CefRunFileDialogCal
     }
   }
   unsafe fn to_rust(c_object: *mut cef_run_file_dialog_callback_t) -> Option<CefRunFileDialogCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRunFileDialogCallback::from_c_object_addref(c_object))
@@ -747,6 +783,165 @@ impl CefWrap<*mut cef_run_file_dialog_callback_t> for Option<CefRunFileDialogCal
 }
 
 
+//
+// Callback structure for cef_browser_host_t::GetNavigationEntries. The
+// functions of this structure will be called on the browser process UI thread.
+//
+#[repr(C)]
+pub struct _cef_navigation_entry_visitor_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Method that will be executed. Do not keep a reference to |entry| outside of
+  // this callback. Return true (1) to continue visiting entries or false (0) to
+  // stop. |current| is true (1) if this entry is the currently loaded
+  // navigation entry. |index| is the 0-based index of this entry and |total| is
+  // the total number of entries.
+  //
+  pub visit: Option<extern "C" fn(this: *mut cef_navigation_entry_visitor_t,
+      entry: *mut interfaces::cef_navigation_entry_t, current: libc::c_int,
+      index: libc::c_int, total: libc::c_int) -> libc::c_int>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_navigation_entry_visitor_t = _cef_navigation_entry_visitor_t;
+
+
+//
+// Callback structure for cef_browser_host_t::GetNavigationEntries. The
+// functions of this structure will be called on the browser process UI thread.
+//
+pub struct CefNavigationEntryVisitor {
+  c_object: *mut cef_navigation_entry_visitor_t,
+}
+
+impl Clone for CefNavigationEntryVisitor {
+  fn clone(&self) -> CefNavigationEntryVisitor{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefNavigationEntryVisitor {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefNavigationEntryVisitor {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefNavigationEntryVisitor {
+  pub unsafe fn from_c_object(c_object: *mut cef_navigation_entry_visitor_t) -> CefNavigationEntryVisitor {
+    CefNavigationEntryVisitor {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_navigation_entry_visitor_t) -> CefNavigationEntryVisitor {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefNavigationEntryVisitor {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_navigation_entry_visitor_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_navigation_entry_visitor_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Method that will be executed. Do not keep a reference to |entry| outside of
+  // this callback. Return true (1) to continue visiting entries or false (0) to
+  // stop. |current| is true (1) if this entry is the currently loaded
+  // navigation entry. |index| is the 0-based index of this entry and |total| is
+  // the total number of entries.
+  //
+  pub fn visit(&self, entry: interfaces::CefNavigationEntry,
+      current: libc::c_int, index: libc::c_int,
+      total: libc::c_int) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).visit.unwrap())(
+          self.c_object,
+          CefWrap::to_c(entry),
+          CefWrap::to_c(current),
+          CefWrap::to_c(index),
+          CefWrap::to_c(total)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_navigation_entry_visitor_t> for CefNavigationEntryVisitor {
+  fn to_c(rust_object: CefNavigationEntryVisitor) -> *mut cef_navigation_entry_visitor_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_navigation_entry_visitor_t) -> CefNavigationEntryVisitor {
+    CefNavigationEntryVisitor::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_navigation_entry_visitor_t> for Option<CefNavigationEntryVisitor> {
+  fn to_c(rust_object: Option<CefNavigationEntryVisitor>) -> *mut cef_navigation_entry_visitor_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_navigation_entry_visitor_t) -> Option<CefNavigationEntryVisitor> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefNavigationEntryVisitor::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
 //
 // Structure used to represent the browser process aspects of a browser window.
 // The functions of this structure can only be called in the browser process.
@@ -837,18 +1032,23 @@ pub struct _cef_browser_host_t {
   // Call to run a file chooser dialog. Only a single file chooser dialog may be
   // pending at any given time. |mode| represents the type of dialog to display.
   // |title| to the title to be used for the dialog and may be NULL to show the
-  // default title ("Open" or "Save" depending on the mode). |default_file_name|
-  // is the default file name to select in the dialog. |accept_types| is a list
-  // of valid lower-cased MIME types or file extensions specified in an input
-  // element and is used to restrict selectable files to such types. |callback|
-  // will be executed after the dialog is dismissed or immediately if another
-  // dialog is already pending. The dialog will be initiated asynchronously on
-  // the UI thread.
+  // default title ("Open" or "Save" depending on the mode). |default_file_path|
+  // is the path with optional directory and/or file name component that will be
+  // initially selected in the dialog. |accept_filters| are used to restrict the
+  // selectable file types and may any combination of (a) valid lower-cased MIME
+  // types (e.g. "text/*" or "image/*"), (b) individual file extensions (e.g.
+  // ".txt" or ".png"), or (c) combined description and file extension delimited
+  // using "|" and ";" (e.g. "Image Types|.png;.gif;.jpg").
+  // |selected_accept_filter| is the 0-based index of the filter that will be
+  // selected by default. |callback| will be executed after the dialog is
+  // dismissed or immediately if another dialog is already pending. The dialog
+  // will be initiated asynchronously on the UI thread.
   //
   pub run_file_dialog: Option<extern "C" fn(this: *mut cef_browser_host_t,
       mode: types::cef_file_dialog_mode_t, title: *const types::cef_string_t,
-      default_file_name: *const types::cef_string_t,
-      accept_types: types::cef_string_list_t,
+      default_file_path: *const types::cef_string_t,
+      accept_filters: types::cef_string_list_t,
+      selected_accept_filter: libc::c_int,
       callback: *mut interfaces::cef_run_file_dialog_callback_t) -> ()>,
 
   //
@@ -864,10 +1064,11 @@ pub struct _cef_browser_host_t {
 
   //
   // Search for |searchText|. |identifier| can be used to have multiple searches
-  // running simultaneously. |forward| indicates whether to search forward or
+  // running simultaniously. |forward| indicates whether to search forward or
   // backward within the page. |matchCase| indicates whether the search should
   // be case-sensitive. |findNext| indicates whether this is the first request
-  // or a follow-up.
+  // or a follow-up. The cef_find_handler_t instance, if any, returned via
+  // cef_client_t::GetFindHandler will be called to report find results.
   //
   pub find: Option<extern "C" fn(this: *mut cef_browser_host_t,
       identifier: libc::c_int, searchText: *const types::cef_string_t,
@@ -897,6 +1098,18 @@ pub struct _cef_browser_host_t {
   pub close_dev_tools: Option<extern "C" fn(this: *mut cef_browser_host_t) -> (
       )>,
 
+  //
+  // Retrieve a snapshot of current navigation entries as values sent to the
+  // specified visitor. If |current_only| is true (1) only the current
+  // navigation entry will be sent, otherwise all navigation entries will be
+  // sent.
+  //
+  //
+  pub get_navigation_entries: Option<extern "C" fn(
+      this: *mut cef_browser_host_t,
+      visitor: *mut interfaces::cef_navigation_entry_visitor_t,
+      current_only: libc::c_int) -> ()>,
+
   //
   // Set whether mouse cursor change is disabled.
   //
@@ -1089,7 +1302,7 @@ pub struct _cef_browser_host_t {
   // being cancelled. |x| and |y| are mouse coordinates relative to the upper-
   // left corner of the view. If the web view is both the drag source and the
   // drag target then all DragTarget* functions should be called before
-  // DragSource* methods. This function is only used when window rendering is
+  // DragSource* mthods. This function is only used when window rendering is
   // disabled.
   //
   pub drag_source_ended_at: Option<extern "C" fn(this: *mut cef_browser_host_t,
@@ -1101,7 +1314,7 @@ pub struct _cef_browser_host_t {
   // cef_render_handler_t::StartDragging call has completed. This function may
   // be called immediately without first calling DragSourceEndedAt to cancel a
   // drag operation. If the web view is both the drag source and the drag target
-  // then all DragTarget* functions should be called before DragSource* methods.
+  // then all DragTarget* functions should be called before DragSource* mthods.
   // This function is only used when window rendering is disabled.
   //
   pub drag_source_system_drag_ended: Option<extern "C" fn(
@@ -1118,13 +1331,13 @@ pub struct _cef_browser_host_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_browser_host_t = _cef_browser_host_t;
 
@@ -1142,7 +1355,8 @@ pub struct CefBrowserHost {
 impl Clone for CefBrowserHost {
   fn clone(&self) -> CefBrowserHost{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBrowserHost {
@@ -1155,7 +1369,8 @@ impl Clone for CefBrowserHost {
 impl Drop for CefBrowserHost {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1170,7 +1385,8 @@ impl CefBrowserHost {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_browser_host_t) -> CefBrowserHost {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBrowserHost {
@@ -1184,7 +1400,8 @@ impl CefBrowserHost {
 
   pub fn c_object_addrefed(&self) -> *mut cef_browser_host_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1192,17 +1409,18 @@ impl CefBrowserHost {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns the hosted browser object.
   //
   pub fn get_browser(&self) -> interfaces::CefBrowser {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1223,7 +1441,8 @@ impl CefBrowserHost {
   // information.
   //
   pub fn close_browser(&self, force_close: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1238,7 +1457,8 @@ impl CefBrowserHost {
   // Set whether the browser is focused.
   //
   pub fn set_focus(&self, focus: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1254,7 +1474,8 @@ impl CefBrowserHost {
   // (minimized/unminimized, app hidden/unhidden, etc). Only used on Mac OS X.
   //
   pub fn set_window_visibility(&self, visible: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1269,7 +1490,8 @@ impl CefBrowserHost {
   // Retrieve the window handle for this browser.
   //
   pub fn get_window_handle(&self) -> types::cef_window_handle_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1285,7 +1507,8 @@ impl CefBrowserHost {
   // with custom handling of modal windows.
   //
   pub fn get_opener_window_handle(&self) -> types::cef_window_handle_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1299,7 +1522,8 @@ impl CefBrowserHost {
   // Returns the client for this browser.
   //
   pub fn get_client(&self) -> interfaces::CefClient {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1313,7 +1537,8 @@ impl CefBrowserHost {
   // Returns the request context for this browser.
   //
   pub fn get_request_context(&self) -> interfaces::CefRequestContext {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1328,7 +1553,8 @@ impl CefBrowserHost {
   // can only be called on the UI thread.
   //
   pub fn get_zoom_level(&self) -> libc::c_double {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1344,7 +1570,8 @@ impl CefBrowserHost {
   // Otherwise, the change will be applied asynchronously on the UI thread.
   //
   pub fn set_zoom_level(&self, zoomLevel: libc::c_double) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1359,18 +1586,24 @@ impl CefBrowserHost {
   // Call to run a file chooser dialog. Only a single file chooser dialog may be
   // pending at any given time. |mode| represents the type of dialog to display.
   // |title| to the title to be used for the dialog and may be NULL to show the
-  // default title ("Open" or "Save" depending on the mode). |default_file_name|
-  // is the default file name to select in the dialog. |accept_types| is a list
-  // of valid lower-cased MIME types or file extensions specified in an input
-  // element and is used to restrict selectable files to such types. |callback|
-  // will be executed after the dialog is dismissed or immediately if another
-  // dialog is already pending. The dialog will be initiated asynchronously on
-  // the UI thread.
+  // default title ("Open" or "Save" depending on the mode). |default_file_path|
+  // is the path with optional directory and/or file name component that will be
+  // initially selected in the dialog. |accept_filters| are used to restrict the
+  // selectable file types and may any combination of (a) valid lower-cased MIME
+  // types (e.g. "text/*" or "image/*"), (b) individual file extensions (e.g.
+  // ".txt" or ".png"), or (c) combined description and file extension delimited
+  // using "|" and ";" (e.g. "Image Types|.png;.gif;.jpg").
+  // |selected_accept_filter| is the 0-based index of the filter that will be
+  // selected by default. |callback| will be executed after the dialog is
+  // dismissed or immediately if another dialog is already pending. The dialog
+  // will be initiated asynchronously on the UI thread.
   //
   pub fn run_file_dialog(&self, mode: types::cef_file_dialog_mode_t,
-      title: &[u16], default_file_name: &[u16], accept_types: Vec<String>,
+      title: &[u16], default_file_path: &[u16], accept_filters: Vec<String>,
+      selected_accept_filter: libc::c_int,
       callback: interfaces::CefRunFileDialogCallback) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1379,8 +1612,9 @@ impl CefBrowserHost {
           self.c_object,
           CefWrap::to_c(mode),
           CefWrap::to_c(title),
-          CefWrap::to_c(default_file_name),
-          CefWrap::to_c(accept_types),
+          CefWrap::to_c(default_file_path),
+          CefWrap::to_c(accept_filters),
+          CefWrap::to_c(selected_accept_filter),
           CefWrap::to_c(callback)))
     }
   }
@@ -1389,7 +1623,8 @@ impl CefBrowserHost {
   // Download the file at |url| using cef_download_handler_t.
   //
   pub fn start_download(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1404,7 +1639,8 @@ impl CefBrowserHost {
   // Print the current browser contents.
   //
   pub fn print(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1416,15 +1652,17 @@ impl CefBrowserHost {
 
   //
   // Search for |searchText|. |identifier| can be used to have multiple searches
-  // running simultaneously. |forward| indicates whether to search forward or
+  // running simultaniously. |forward| indicates whether to search forward or
   // backward within the page. |matchCase| indicates whether the search should
   // be case-sensitive. |findNext| indicates whether this is the first request
-  // or a follow-up.
+  // or a follow-up. The cef_find_handler_t instance, if any, returned via
+  // cef_client_t::GetFindHandler will be called to report find results.
   //
   pub fn find(&self, identifier: libc::c_int, searchText: &[u16],
       forward: libc::c_int, matchCase: libc::c_int, findNext: libc::c_int) -> (
       ) {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1443,7 +1681,8 @@ impl CefBrowserHost {
   // Cancel all searches that are currently going on.
   //
   pub fn stop_finding(&self, clearSelection: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1461,7 +1700,8 @@ impl CefBrowserHost {
   pub fn show_dev_tools(&self, windowInfo: &interfaces::CefWindowInfo,
       client: interfaces::CefClient, settings: &interfaces::CefBrowserSettings,
       inspect_element_at: &types::cef_point_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1480,7 +1720,8 @@ impl CefBrowserHost {
   // instance.
   //
   pub fn close_dev_tools(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1490,11 +1731,35 @@ impl CefBrowserHost {
     }
   }
 
+  //
+  // Retrieve a snapshot of current navigation entries as values sent to the
+  // specified visitor. If |current_only| is true (1) only the current
+  // navigation entry will be sent, otherwise all navigation entries will be
+  // sent.
+  //
+  //
+  pub fn get_navigation_entries(&self,
+      visitor: interfaces::CefNavigationEntryVisitor,
+      current_only: libc::c_int) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_navigation_entries.unwrap())(
+          self.c_object,
+          CefWrap::to_c(visitor),
+          CefWrap::to_c(current_only)))
+    }
+  }
+
   //
   // Set whether mouse cursor change is disabled.
   //
   pub fn set_mouse_cursor_change_disabled(&self, disabled: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1509,7 +1774,8 @@ impl CefBrowserHost {
   // Returns true (1) if mouse cursor change is disabled.
   //
   pub fn is_mouse_cursor_change_disabled(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1524,7 +1790,8 @@ impl CefBrowserHost {
   // function will replace it with the specified |word|.
   //
   pub fn replace_misspelling(&self, word: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1539,7 +1806,8 @@ impl CefBrowserHost {
   // Add the specified |word| to the spelling dictionary.
   //
   pub fn add_word_to_dictionary(&self, word: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1554,7 +1822,8 @@ impl CefBrowserHost {
   // Returns true (1) if window rendering is disabled.
   //
   pub fn is_window_rendering_disabled(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1571,7 +1840,8 @@ impl CefBrowserHost {
   // function is only used when window rendering is disabled.
   //
   pub fn was_resized(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1587,7 +1857,8 @@ impl CefBrowserHost {
   // hidden. This function is only used when window rendering is disabled.
   //
   pub fn was_hidden(&self, hidden: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1607,7 +1878,8 @@ impl CefBrowserHost {
   // disabled.
   //
   pub fn notify_screen_info_changed(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1623,7 +1895,8 @@ impl CefBrowserHost {
   // disabled.
   //
   pub fn invalidate(&self, ty: types::cef_paint_element_type_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1638,7 +1911,8 @@ impl CefBrowserHost {
   // Send a key event to the browser.
   //
   pub fn send_key_event(&self, event: &interfaces::CefKeyEvent) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1656,7 +1930,8 @@ impl CefBrowserHost {
   pub fn send_mouse_click_event(&self, event: &interfaces::CefMouseEvent,
       ty: types::cef_mouse_button_type_t, mouseUp: libc::c_int,
       clickCount: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1676,7 +1951,8 @@ impl CefBrowserHost {
   //
   pub fn send_mouse_move_event(&self, event: &interfaces::CefMouseEvent,
       mouseLeave: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1697,7 +1973,8 @@ impl CefBrowserHost {
   //
   pub fn send_mouse_wheel_event(&self, event: &interfaces::CefMouseEvent,
       deltaX: libc::c_int, deltaY: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1714,7 +1991,8 @@ impl CefBrowserHost {
   // Send a focus event to the browser.
   //
   pub fn send_focus_event(&self, setFocus: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1729,7 +2007,8 @@ impl CefBrowserHost {
   // Send a capture lost event to the browser.
   //
   pub fn send_capture_lost_event(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1744,7 +2023,8 @@ impl CefBrowserHost {
   // resized. This function is only used on Windows and Linux.
   //
   pub fn notify_move_or_resize_started(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1759,7 +2039,8 @@ impl CefBrowserHost {
   // window rendering is disabled.
   //
   pub fn get_nstext_input_context(&self) -> types::cef_text_input_context_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1775,7 +2056,8 @@ impl CefBrowserHost {
   //
   pub fn handle_key_event_before_text_input_client(&self,
       keyEvent: types::cef_event_handle_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1791,7 +2073,8 @@ impl CefBrowserHost {
   //
   pub fn handle_key_event_after_text_input_client(&self,
       keyEvent: types::cef_event_handle_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1814,7 +2097,8 @@ impl CefBrowserHost {
   pub fn drag_target_drag_enter(&self, drag_data: interfaces::CefDragData,
       event: &interfaces::CefMouseEvent,
       allowed_ops: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1835,7 +2119,8 @@ impl CefBrowserHost {
   //
   pub fn drag_target_drag_over(&self, event: &interfaces::CefMouseEvent,
       allowed_ops: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1853,7 +2138,8 @@ impl CefBrowserHost {
   // rendering is disabled.
   //
   pub fn drag_target_drag_leave(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1871,7 +2157,8 @@ impl CefBrowserHost {
   // is disabled.
   //
   pub fn drag_target_drop(&self, event: &interfaces::CefMouseEvent) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1888,12 +2175,13 @@ impl CefBrowserHost {
   // being cancelled. |x| and |y| are mouse coordinates relative to the upper-
   // left corner of the view. If the web view is both the drag source and the
   // drag target then all DragTarget* functions should be called before
-  // DragSource* methods. This function is only used when window rendering is
+  // DragSource* mthods. This function is only used when window rendering is
   // disabled.
   //
   pub fn drag_source_ended_at(&self, x: libc::c_int, y: libc::c_int,
       op: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1911,11 +2199,12 @@ impl CefBrowserHost {
   // cef_render_handler_t::StartDragging call has completed. This function may
   // be called immediately without first calling DragSourceEndedAt to cancel a
   // drag operation. If the web view is both the drag source and the drag target
-  // then all DragTarget* functions should be called before DragSource* methods.
+  // then all DragTarget* functions should be called before DragSource* mthods.
   // This function is only used when window rendering is disabled.
   //
   pub fn drag_source_system_drag_ended(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1931,7 +2220,8 @@ impl CefBrowserHost {
   // this function.
   //
   pub fn initialize_compositing(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2000,7 +2290,8 @@ impl CefWrap<*mut cef_browser_host_t> for Option<CefBrowserHost> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_browser_host_t) -> Option<CefBrowserHost> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefBrowserHost::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_browser_process_handler.rs b/servo/ports/cef/interfaces/cef_browser_process_handler.rs
index 66ba7a0635d3..672247169fda 100644
--- a/servo/ports/cef/interfaces/cef_browser_process_handler.rs
+++ b/servo/ports/cef/interfaces/cef_browser_process_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -96,13 +97,13 @@ pub struct _cef_browser_process_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_browser_process_handler_t = _cef_browser_process_handler_t;
 
@@ -119,7 +120,8 @@ pub struct CefBrowserProcessHandler {
 impl Clone for CefBrowserProcessHandler {
   fn clone(&self) -> CefBrowserProcessHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBrowserProcessHandler {
@@ -132,7 +134,8 @@ impl Clone for CefBrowserProcessHandler {
 impl Drop for CefBrowserProcessHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -147,7 +150,8 @@ impl CefBrowserProcessHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_browser_process_handler_t) -> CefBrowserProcessHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBrowserProcessHandler {
@@ -161,7 +165,8 @@ impl CefBrowserProcessHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_browser_process_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -169,10 +174,10 @@ impl CefBrowserProcessHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -180,7 +185,8 @@ impl CefBrowserProcessHandler {
   // has been initialized.
   //
   pub fn on_context_initialized(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -199,7 +205,8 @@ impl CefBrowserProcessHandler {
   //
   pub fn on_before_child_process_launch(&self,
       command_line: interfaces::CefCommandLine) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -219,7 +226,8 @@ impl CefBrowserProcessHandler {
   //
   pub fn on_render_process_thread_created(&self,
       extra_info: interfaces::CefListValue) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -235,7 +243,8 @@ impl CefBrowserProcessHandler {
   // provided then printing will not be supported on the Linux platform.
   //
   pub fn get_print_handler(&self) -> interfaces::CefPrintHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -262,7 +271,8 @@ impl CefWrap<*mut cef_browser_process_handler_t> for Option<CefBrowserProcessHan
     }
   }
   unsafe fn to_rust(c_object: *mut cef_browser_process_handler_t) -> Option<CefBrowserProcessHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefBrowserProcessHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_callback.rs b/servo/ports/cef/interfaces/cef_callback.rs
index a4b8fe54a22e..ef2452ff71d6 100644
--- a/servo/ports/cef/interfaces/cef_callback.rs
+++ b/servo/ports/cef/interfaces/cef_callback.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -68,13 +69,13 @@ pub struct _cef_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_callback_t = _cef_callback_t;
 
@@ -89,7 +90,8 @@ pub struct CefCallback {
 impl Clone for CefCallback {
   fn clone(&self) -> CefCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCallback {
@@ -102,7 +104,8 @@ impl Clone for CefCallback {
 impl Drop for CefCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -117,7 +120,8 @@ impl CefCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_callback_t) -> CefCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCallback {
@@ -131,7 +135,8 @@ impl CefCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -139,17 +144,18 @@ impl CefCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Continue processing.
   //
   pub fn cont(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -163,7 +169,8 @@ impl CefCallback {
   // Cancel processing.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -190,7 +197,8 @@ impl CefWrap<*mut cef_callback_t> for Option<CefCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_callback_t) -> Option<CefCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefCallback::from_c_object_addref(c_object))
@@ -218,13 +226,13 @@ pub struct _cef_completion_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_completion_callback_t = _cef_completion_callback_t;
 
@@ -239,7 +247,8 @@ pub struct CefCompletionCallback {
 impl Clone for CefCompletionCallback {
   fn clone(&self) -> CefCompletionCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCompletionCallback {
@@ -252,7 +261,8 @@ impl Clone for CefCompletionCallback {
 impl Drop for CefCompletionCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -267,7 +277,8 @@ impl CefCompletionCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_completion_callback_t) -> CefCompletionCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCompletionCallback {
@@ -281,7 +292,8 @@ impl CefCompletionCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_completion_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -289,17 +301,18 @@ impl CefCompletionCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Method that will be called once the task is complete.
   //
   pub fn on_complete(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -326,7 +339,8 @@ impl CefWrap<*mut cef_completion_callback_t> for Option<CefCompletionCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_completion_callback_t) -> Option<CefCompletionCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefCompletionCallback::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_client.rs b/servo/ports/cef/interfaces/cef_client.rs
index 3c75868c9b0b..e49632d5f96e 100644
--- a/servo/ports/cef/interfaces/cef_client.rs
+++ b/servo/ports/cef/interfaces/cef_client.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -88,6 +89,12 @@ pub struct _cef_client_t {
   pub get_drag_handler: Option<extern "C" fn(
       this: *mut cef_client_t) -> *mut interfaces::cef_drag_handler_t>,
 
+  //
+  // Return the handler for find result events.
+  //
+  pub get_find_handler: Option<extern "C" fn(
+      this: *mut cef_client_t) -> *mut interfaces::cef_find_handler_t>,
+
   //
   // Return the handler for focus events.
   //
@@ -151,13 +158,13 @@ pub struct _cef_client_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_client_t = _cef_client_t;
 
@@ -172,7 +179,8 @@ pub struct CefClient {
 impl Clone for CefClient {
   fn clone(&self) -> CefClient{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefClient {
@@ -185,7 +193,8 @@ impl Clone for CefClient {
 impl Drop for CefClient {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -200,7 +209,8 @@ impl CefClient {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_client_t) -> CefClient {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefClient {
@@ -214,7 +224,8 @@ impl CefClient {
 
   pub fn c_object_addrefed(&self) -> *mut cef_client_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -222,10 +233,10 @@ impl CefClient {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -233,7 +244,8 @@ impl CefClient {
   // implementation will be used.
   //
   pub fn get_context_menu_handler(&self) -> interfaces::CefContextMenuHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -248,7 +260,8 @@ impl CefClient {
   // implementation will be used.
   //
   pub fn get_dialog_handler(&self) -> interfaces::CefDialogHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -262,7 +275,8 @@ impl CefClient {
   // Return the handler for browser display state events.
   //
   pub fn get_display_handler(&self) -> interfaces::CefDisplayHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -277,7 +291,8 @@ impl CefClient {
   // will not be allowed.
   //
   pub fn get_download_handler(&self) -> interfaces::CefDownloadHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,7 +306,8 @@ impl CefClient {
   // Return the handler for drag events.
   //
   pub fn get_drag_handler(&self) -> interfaces::CefDragHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -301,11 +317,27 @@ impl CefClient {
     }
   }
 
+  //
+  // Return the handler for find result events.
+  //
+  pub fn get_find_handler(&self) -> interfaces::CefFindHandler {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_find_handler.unwrap())(
+          self.c_object))
+    }
+  }
+
   //
   // Return the handler for focus events.
   //
   pub fn get_focus_handler(&self) -> interfaces::CefFocusHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -320,7 +352,8 @@ impl CefClient {
   // provided geolocation access will be denied by default.
   //
   pub fn get_geolocation_handler(&self) -> interfaces::CefGeolocationHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -335,7 +368,8 @@ impl CefClient {
   // default implementation will be used.
   //
   pub fn get_jsdialog_handler(&self) -> interfaces::CefJSDialogHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -349,7 +383,8 @@ impl CefClient {
   // Return the handler for keyboard events.
   //
   pub fn get_keyboard_handler(&self) -> interfaces::CefKeyboardHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -363,7 +398,8 @@ impl CefClient {
   // Return the handler for browser life span events.
   //
   pub fn get_life_span_handler(&self) -> interfaces::CefLifeSpanHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -377,7 +413,8 @@ impl CefClient {
   // Return the handler for browser load status events.
   //
   pub fn get_load_handler(&self) -> interfaces::CefLoadHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -391,7 +428,8 @@ impl CefClient {
   // Return the handler for off-screen rendering events.
   //
   pub fn get_render_handler(&self) -> interfaces::CefRenderHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -405,7 +443,8 @@ impl CefClient {
   // Return the handler for browser request events.
   //
   pub fn get_request_handler(&self) -> interfaces::CefRequestHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -423,7 +462,8 @@ impl CefClient {
   pub fn on_process_message_received(&self, browser: interfaces::CefBrowser,
       source_process: interfaces::CefProcessId,
       message: interfaces::CefProcessMessage) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -453,7 +493,8 @@ impl CefWrap<*mut cef_client_t> for Option<CefClient> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_client_t) -> Option<CefClient> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefClient::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_command_line.rs b/servo/ports/cef/interfaces/cef_command_line.rs
index 1524296b6e1b..53674ef25baf 100644
--- a/servo/ports/cef/interfaces/cef_command_line.rs
+++ b/servo/ports/cef/interfaces/cef_command_line.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -200,13 +201,13 @@ pub struct _cef_command_line_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_command_line_t = _cef_command_line_t;
 
@@ -228,7 +229,8 @@ pub struct CefCommandLine {
 impl Clone for CefCommandLine {
   fn clone(&self) -> CefCommandLine{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCommandLine {
@@ -241,7 +243,8 @@ impl Clone for CefCommandLine {
 impl Drop for CefCommandLine {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -256,7 +259,8 @@ impl CefCommandLine {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_command_line_t) -> CefCommandLine {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCommandLine {
@@ -270,7 +274,8 @@ impl CefCommandLine {
 
   pub fn c_object_addrefed(&self) -> *mut cef_command_line_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -278,10 +283,10 @@ impl CefCommandLine {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -289,7 +294,8 @@ impl CefCommandLine {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -304,7 +310,8 @@ impl CefCommandLine {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -318,7 +325,8 @@ impl CefCommandLine {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefCommandLine {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -334,7 +342,8 @@ impl CefCommandLine {
   // supported on non-Windows platforms.
   //
   pub fn init_from_argv(&self, argc: libc::c_int, argv: &&str) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -351,7 +360,8 @@ impl CefCommandLine {
   // GetCommandLineW(). This function is only supported on Windows.
   //
   pub fn init_from_string(&self, command_line: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -367,7 +377,8 @@ impl CefCommandLine {
   // component unchanged.
   //
   pub fn reset(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -382,7 +393,8 @@ impl CefCommandLine {
   // array: { program, [(--|-|/)switch[=value]]*, [--], [argument]* }
   //
   pub fn get_argv(&self, argv: Vec<String>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -399,7 +411,8 @@ impl CefCommandLine {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_command_line_string(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -414,7 +427,8 @@ impl CefCommandLine {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_program(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -428,7 +442,8 @@ impl CefCommandLine {
   // Set the program part of the command line string (the first item).
   //
   pub fn set_program(&self, program: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -443,7 +458,8 @@ impl CefCommandLine {
   // Returns true (1) if the command line has switches.
   //
   pub fn has_switches(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -457,7 +473,8 @@ impl CefCommandLine {
   // Returns true (1) if the command line contains the given switch.
   //
   pub fn has_switch(&self, name: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -474,7 +491,8 @@ impl CefCommandLine {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_switch_value(&self, name: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -490,7 +508,8 @@ impl CefCommandLine {
   // NULL string is returned.
   //
   pub fn get_switches(&self, switches: HashMap<String,String>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -506,7 +525,8 @@ impl CefCommandLine {
   // pass an NULL value string.
   //
   pub fn append_switch(&self, name: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -521,7 +541,8 @@ impl CefCommandLine {
   // Add a switch with the specified value to the end of the command line.
   //
   pub fn append_switch_with_value(&self, name: &[u16], value: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -537,7 +558,8 @@ impl CefCommandLine {
   // True if there are remaining command line arguments.
   //
   pub fn has_arguments(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -551,7 +573,8 @@ impl CefCommandLine {
   // Get the remaining command line arguments.
   //
   pub fn get_arguments(&self, arguments: Vec<String>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -566,7 +589,8 @@ impl CefCommandLine {
   // Add an argument to the end of the command line.
   //
   pub fn append_argument(&self, argument: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -582,7 +606,8 @@ impl CefCommandLine {
   // "valgrind" or "gdb --args".
   //
   pub fn prepend_wrapper(&self, wrapper: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -633,7 +658,8 @@ impl CefWrap<*mut cef_command_line_t> for Option<CefCommandLine> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_command_line_t) -> Option<CefCommandLine> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefCommandLine::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_context_menu_handler.rs b/servo/ports/cef/interfaces/cef_context_menu_handler.rs
index a3863c491bfe..dedb9fd5c645 100644
--- a/servo/ports/cef/interfaces/cef_context_menu_handler.rs
+++ b/servo/ports/cef/interfaces/cef_context_menu_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -99,13 +100,13 @@ pub struct _cef_context_menu_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_context_menu_handler_t = _cef_context_menu_handler_t;
 
@@ -121,7 +122,8 @@ pub struct CefContextMenuHandler {
 impl Clone for CefContextMenuHandler {
   fn clone(&self) -> CefContextMenuHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefContextMenuHandler {
@@ -134,7 +136,8 @@ impl Clone for CefContextMenuHandler {
 impl Drop for CefContextMenuHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -149,7 +152,8 @@ impl CefContextMenuHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_context_menu_handler_t) -> CefContextMenuHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefContextMenuHandler {
@@ -163,7 +167,8 @@ impl CefContextMenuHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_context_menu_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -171,10 +176,10 @@ impl CefContextMenuHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -187,7 +192,8 @@ impl CefContextMenuHandler {
   pub fn on_before_context_menu(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, params: interfaces::CefContextMenuParams,
       model: interfaces::CefMenuModel) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -214,7 +220,8 @@ impl CefContextMenuHandler {
       frame: interfaces::CefFrame, params: interfaces::CefContextMenuParams,
       command_id: libc::c_int,
       event_flags: types::cef_event_flags_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -235,7 +242,8 @@ impl CefContextMenuHandler {
   //
   pub fn on_context_menu_dismissed(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -264,7 +272,8 @@ impl CefWrap<*mut cef_context_menu_handler_t> for Option<CefContextMenuHandler>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_context_menu_handler_t) -> Option<CefContextMenuHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefContextMenuHandler::from_c_object_addref(c_object))
@@ -274,7 +283,7 @@ impl CefWrap<*mut cef_context_menu_handler_t> for Option<CefContextMenuHandler>
 
 
 //
-// Provides information about the context menu state. The methods of this
+// Provides information about the context menu state. The ethods of this
 // structure can only be accessed on browser process the UI thread.
 //
 #[repr(C)]
@@ -387,13 +396,6 @@ pub struct _cef_context_menu_params_t {
   pub get_misspelled_word: Option<extern "C" fn(
       this: *mut cef_context_menu_params_t) -> types::cef_string_userfree_t>,
 
-  //
-  // Returns the hash of the misspelled word, if any, that the context menu was
-  // invoked on.
-  //
-  pub get_misspelling_hash: Option<extern "C" fn(
-      this: *mut cef_context_menu_params_t) -> libc::c_int>,
-
   //
   // Returns true (1) if suggestions exist, false (0) otherwise. Fills in
   // |suggestions| from the spell check service for the misspelled word if there
@@ -426,19 +428,19 @@ pub struct _cef_context_menu_params_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_context_menu_params_t = _cef_context_menu_params_t;
 
 
 //
-// Provides information about the context menu state. The methods of this
+// Provides information about the context menu state. The ethods of this
 // structure can only be accessed on browser process the UI thread.
 //
 pub struct CefContextMenuParams {
@@ -448,7 +450,8 @@ pub struct CefContextMenuParams {
 impl Clone for CefContextMenuParams {
   fn clone(&self) -> CefContextMenuParams{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefContextMenuParams {
@@ -461,7 +464,8 @@ impl Clone for CefContextMenuParams {
 impl Drop for CefContextMenuParams {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -476,7 +480,8 @@ impl CefContextMenuParams {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_context_menu_params_t) -> CefContextMenuParams {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefContextMenuParams {
@@ -490,7 +495,8 @@ impl CefContextMenuParams {
 
   pub fn c_object_addrefed(&self) -> *mut cef_context_menu_params_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -498,10 +504,10 @@ impl CefContextMenuParams {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -509,7 +515,8 @@ impl CefContextMenuParams {
   // Coords are relative to the associated RenderView's origin.
   //
   pub fn get_xcoord(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -524,7 +531,8 @@ impl CefContextMenuParams {
   // Coords are relative to the associated RenderView's origin.
   //
   pub fn get_ycoord(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -539,7 +547,8 @@ impl CefContextMenuParams {
   // invoked on.
   //
   pub fn get_type_flags(&self) -> types::cef_context_menu_type_flags_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -555,7 +564,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -571,7 +581,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_unfiltered_link_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -587,7 +598,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_source_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -602,7 +614,8 @@ impl CefContextMenuParams {
   // NULL contents.
   //
   pub fn has_image_contents(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -617,7 +630,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_page_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -632,7 +646,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_frame_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -648,7 +663,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_frame_charset(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -662,7 +678,8 @@ impl CefContextMenuParams {
   // Returns the type of context node that the context menu was invoked on.
   //
   pub fn get_media_type(&self) -> types::cef_context_menu_media_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -678,7 +695,8 @@ impl CefContextMenuParams {
   //
   pub fn get_media_state_flags(
       &self) -> types::cef_context_menu_media_state_flags_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -694,7 +712,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_selection_text(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -710,7 +729,8 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_misspelled_word(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -720,21 +740,6 @@ impl CefContextMenuParams {
     }
   }
 
-  //
-  // Returns the hash of the misspelled word, if any, that the context menu was
-  // invoked on.
-  //
-  pub fn get_misspelling_hash(&self) -> libc::c_int {
-    if self.c_object.is_null() {
-      panic!("called a CEF method on a null object")
-    }
-    unsafe {
-      CefWrap::to_rust(
-        ((*self.c_object).get_misspelling_hash.unwrap())(
-          self.c_object))
-    }
-  }
-
   //
   // Returns true (1) if suggestions exist, false (0) otherwise. Fills in
   // |suggestions| from the spell check service for the misspelled word if there
@@ -742,7 +747,8 @@ impl CefContextMenuParams {
   //
   pub fn get_dictionary_suggestions(&self,
       suggestions: Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -757,7 +763,8 @@ impl CefContextMenuParams {
   // Returns true (1) if the context menu was invoked on an editable node.
   //
   pub fn is_editable(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -772,7 +779,8 @@ impl CefContextMenuParams {
   // spell-check is enabled.
   //
   pub fn is_spell_check_enabled(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -788,7 +796,8 @@ impl CefContextMenuParams {
   //
   pub fn get_edit_state_flags(
       &self) -> types::cef_context_menu_edit_state_flags_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -815,7 +824,8 @@ impl CefWrap<*mut cef_context_menu_params_t> for Option<CefContextMenuParams> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_context_menu_params_t) -> Option<CefContextMenuParams> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefContextMenuParams::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_cookie.rs b/servo/ports/cef/interfaces/cef_cookie.rs
index 4239c95c67e0..1b1090e94998 100644
--- a/servo/ports/cef/interfaces/cef_cookie.rs
+++ b/servo/ports/cef/interfaces/cef_cookie.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -58,26 +59,28 @@ pub struct _cef_cookie_manager_t {
 
   //
   // Set the schemes supported by this manager. By default only "http" and
-  // "https" schemes are supported. Must be called before any cookies are
-  // accessed.
+  // "https" schemes are supported. If |callback| is non-NULL it will be
+  // executed asnychronously on the IO thread after the change has been applied.
+  // Must be called before any cookies are accessed.
   //
   pub set_supported_schemes: Option<extern "C" fn(
-      this: *mut cef_cookie_manager_t, schemes: types::cef_string_list_t) -> (
-      )>,
+      this: *mut cef_cookie_manager_t, schemes: types::cef_string_list_t,
+      callback: *mut interfaces::cef_completion_callback_t) -> ()>,
 
   //
-  // Visit all cookies. The returned cookies are ordered by longest path, then
-  // by earliest creation date. Returns false (0) if cookies cannot be accessed.
+  // Visit all cookies on the IO thread. The returned cookies are ordered by
+  // longest path, then by earliest creation date. Returns false (0) if cookies
+  // cannot be accessed.
   //
   pub visit_all_cookies: Option<extern "C" fn(this: *mut cef_cookie_manager_t,
       visitor: *mut interfaces::cef_cookie_visitor_t) -> libc::c_int>,
 
   //
-  // Visit a subset of cookies. The results are filtered by the given url
-  // scheme, host, domain and path. If |includeHttpOnly| is true (1) HTTP-only
-  // cookies will also be included in the results. The returned cookies are
-  // ordered by longest path, then by earliest creation date. Returns false (0)
-  // if cookies cannot be accessed.
+  // Visit a subset of cookies on the IO thread. The results are filtered by the
+  // given url scheme, host, domain and path. If |includeHttpOnly| is true (1)
+  // HTTP-only cookies will also be included in the results. The returned
+  // cookies are ordered by longest path, then by earliest creation date.
+  // Returns false (0) if cookies cannot be accessed.
   //
   pub visit_url_cookies: Option<extern "C" fn(this: *mut cef_cookie_manager_t,
       url: *const types::cef_string_t, includeHttpOnly: libc::c_int,
@@ -87,26 +90,29 @@ pub struct _cef_cookie_manager_t {
   // Sets a cookie given a valid URL and explicit user-provided cookie
   // attributes. This function expects each attribute to be well-formed. It will
   // check for disallowed characters (e.g. the ';' character is disallowed
-  // within the cookie value attribute) and will return false (0) without
-  // setting the cookie if such characters are found. This function must be
-  // called on the IO thread.
+  // within the cookie value attribute) and fail without setting the cookie if
+  // such characters are found. If |callback| is non-NULL it will be executed
+  // asnychronously on the IO thread after the cookie has been set. Returns
+  // false (0) if an invalid URL is specified or if cookies cannot be accessed.
   //
   pub set_cookie: Option<extern "C" fn(this: *mut cef_cookie_manager_t,
-      url: *const types::cef_string_t,
-      cookie: *const interfaces::cef_cookie_t) -> libc::c_int>,
+      url: *const types::cef_string_t, cookie: *const interfaces::cef_cookie_t,
+      callback: *mut interfaces::cef_set_cookie_callback_t) -> libc::c_int>,
 
   //
   // Delete all cookies that match the specified parameters. If both |url| and
-  // values |cookie_name| are specified all host and domain cookies matching
+  // |cookie_name| values are specified all host and domain cookies matching
   // both will be deleted. If only |url| is specified all host cookies (but not
   // domain cookies) irrespective of path will be deleted. If |url| is NULL all
-  // cookies for all hosts and domains will be deleted. Returns false (0) if a
-  // non- NULL invalid URL is specified or if cookies cannot be accessed. This
-  // function must be called on the IO thread.
+  // cookies for all hosts and domains will be deleted. If |callback| is non-
+  // NULL it will be executed asnychronously on the IO thread after the cookies
+  // have been deleted. Returns false (0) if a non-NULL invalid URL is specified
+  // or if cookies cannot be accessed. Cookies can alternately be deleted using
+  // the Visit*Cookies() functions.
   //
   pub delete_cookies: Option<extern "C" fn(this: *mut cef_cookie_manager_t,
-      url: *const types::cef_string_t,
-      cookie_name: *const types::cef_string_t) -> libc::c_int>,
+      url: *const types::cef_string_t, cookie_name: *const types::cef_string_t,
+      callback: *mut interfaces::cef_delete_cookies_callback_t) -> libc::c_int>,
 
   //
   // Sets the directory path that will be used for storing cookie data. If
@@ -114,17 +120,18 @@ pub struct _cef_cookie_manager_t {
   // stored at the specified |path|. To persist session cookies (cookies without
   // an expiry date or validity interval) set |persist_session_cookies| to true
   // (1). Session cookies are generally intended to be transient and most Web
-  // browsers do not persist them. Returns false (0) if cookies cannot be
-  // accessed.
+  // browsers do not persist them. If |callback| is non-NULL it will be executed
+  // asnychronously on the IO thread after the manager's storage has been
+  // initialized. Returns false (0) if cookies cannot be accessed.
   //
   pub set_storage_path: Option<extern "C" fn(this: *mut cef_cookie_manager_t,
-      path: *const types::cef_string_t,
-      persist_session_cookies: libc::c_int) -> libc::c_int>,
+      path: *const types::cef_string_t, persist_session_cookies: libc::c_int,
+      callback: *mut interfaces::cef_completion_callback_t) -> libc::c_int>,
 
   //
-  // Flush the backing store (if any) to disk and execute the specified
-  // |callback| on the IO thread when done. Returns false (0) if cookies cannot
-  // be accessed.
+  // Flush the backing store (if any) to disk. If |callback| is non-NULL it will
+  // be executed asnychronously on the IO thread after the flush is complete.
+  // Returns false (0) if cookies cannot be accessed.
   //
   pub flush_store: Option<extern "C" fn(this: *mut cef_cookie_manager_t,
       callback: *mut interfaces::cef_completion_callback_t) -> libc::c_int>,
@@ -132,13 +139,13 @@ pub struct _cef_cookie_manager_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_cookie_manager_t = _cef_cookie_manager_t;
 
@@ -154,7 +161,8 @@ pub struct CefCookieManager {
 impl Clone for CefCookieManager {
   fn clone(&self) -> CefCookieManager{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCookieManager {
@@ -167,7 +175,8 @@ impl Clone for CefCookieManager {
 impl Drop for CefCookieManager {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -182,7 +191,8 @@ impl CefCookieManager {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_cookie_manager_t) -> CefCookieManager {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCookieManager {
@@ -196,7 +206,8 @@ impl CefCookieManager {
 
   pub fn c_object_addrefed(&self) -> *mut cef_cookie_manager_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -204,36 +215,42 @@ impl CefCookieManager {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Set the schemes supported by this manager. By default only "http" and
-  // "https" schemes are supported. Must be called before any cookies are
-  // accessed.
+  // "https" schemes are supported. If |callback| is non-NULL it will be
+  // executed asnychronously on the IO thread after the change has been applied.
+  // Must be called before any cookies are accessed.
   //
-  pub fn set_supported_schemes(&self, schemes: Vec<String>) -> () {
-    if self.c_object.is_null() {
+  pub fn set_supported_schemes(&self, schemes: Vec<String>,
+      callback: interfaces::CefCompletionCallback) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
       CefWrap::to_rust(
         ((*self.c_object).set_supported_schemes.unwrap())(
           self.c_object,
-          CefWrap::to_c(schemes)))
+          CefWrap::to_c(schemes),
+          CefWrap::to_c(callback)))
     }
   }
 
   //
-  // Visit all cookies. The returned cookies are ordered by longest path, then
-  // by earliest creation date. Returns false (0) if cookies cannot be accessed.
+  // Visit all cookies on the IO thread. The returned cookies are ordered by
+  // longest path, then by earliest creation date. Returns false (0) if cookies
+  // cannot be accessed.
   //
   pub fn visit_all_cookies(&self,
       visitor: interfaces::CefCookieVisitor) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -245,15 +262,16 @@ impl CefCookieManager {
   }
 
   //
-  // Visit a subset of cookies. The results are filtered by the given url
-  // scheme, host, domain and path. If |includeHttpOnly| is true (1) HTTP-only
-  // cookies will also be included in the results. The returned cookies are
-  // ordered by longest path, then by earliest creation date. Returns false (0)
-  // if cookies cannot be accessed.
+  // Visit a subset of cookies on the IO thread. The results are filtered by the
+  // given url scheme, host, domain and path. If |includeHttpOnly| is true (1)
+  // HTTP-only cookies will also be included in the results. The returned
+  // cookies are ordered by longest path, then by earliest creation date.
+  // Returns false (0) if cookies cannot be accessed.
   //
   pub fn visit_url_cookies(&self, url: &[u16], includeHttpOnly: libc::c_int,
       visitor: interfaces::CefCookieVisitor) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -270,13 +288,15 @@ impl CefCookieManager {
   // Sets a cookie given a valid URL and explicit user-provided cookie
   // attributes. This function expects each attribute to be well-formed. It will
   // check for disallowed characters (e.g. the ';' character is disallowed
-  // within the cookie value attribute) and will return false (0) without
-  // setting the cookie if such characters are found. This function must be
-  // called on the IO thread.
+  // within the cookie value attribute) and fail without setting the cookie if
+  // such characters are found. If |callback| is non-NULL it will be executed
+  // asnychronously on the IO thread after the cookie has been set. Returns
+  // false (0) if an invalid URL is specified or if cookies cannot be accessed.
   //
-  pub fn set_cookie(&self, url: &[u16],
-      cookie: &interfaces::CefCookie) -> libc::c_int {
-    if self.c_object.is_null() {
+  pub fn set_cookie(&self, url: &[u16], cookie: &interfaces::CefCookie,
+      callback: interfaces::CefSetCookieCallback) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -284,22 +304,26 @@ impl CefCookieManager {
         ((*self.c_object).set_cookie.unwrap())(
           self.c_object,
           CefWrap::to_c(url),
-          CefWrap::to_c(cookie)))
+          CefWrap::to_c(cookie),
+          CefWrap::to_c(callback)))
     }
   }
 
   //
   // Delete all cookies that match the specified parameters. If both |url| and
-  // values |cookie_name| are specified all host and domain cookies matching
+  // |cookie_name| values are specified all host and domain cookies matching
   // both will be deleted. If only |url| is specified all host cookies (but not
   // domain cookies) irrespective of path will be deleted. If |url| is NULL all
-  // cookies for all hosts and domains will be deleted. Returns false (0) if a
-  // non- NULL invalid URL is specified or if cookies cannot be accessed. This
-  // function must be called on the IO thread.
+  // cookies for all hosts and domains will be deleted. If |callback| is non-
+  // NULL it will be executed asnychronously on the IO thread after the cookies
+  // have been deleted. Returns false (0) if a non-NULL invalid URL is specified
+  // or if cookies cannot be accessed. Cookies can alternately be deleted using
+  // the Visit*Cookies() functions.
   //
-  pub fn delete_cookies(&self, url: &[u16],
-      cookie_name: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+  pub fn delete_cookies(&self, url: &[u16], cookie_name: &[u16],
+      callback: interfaces::CefDeleteCookiesCallback) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -307,7 +331,8 @@ impl CefCookieManager {
         ((*self.c_object).delete_cookies.unwrap())(
           self.c_object,
           CefWrap::to_c(url),
-          CefWrap::to_c(cookie_name)))
+          CefWrap::to_c(cookie_name),
+          CefWrap::to_c(callback)))
     }
   }
 
@@ -317,12 +342,15 @@ impl CefCookieManager {
   // stored at the specified |path|. To persist session cookies (cookies without
   // an expiry date or validity interval) set |persist_session_cookies| to true
   // (1). Session cookies are generally intended to be transient and most Web
-  // browsers do not persist them. Returns false (0) if cookies cannot be
-  // accessed.
+  // browsers do not persist them. If |callback| is non-NULL it will be executed
+  // asnychronously on the IO thread after the manager's storage has been
+  // initialized. Returns false (0) if cookies cannot be accessed.
   //
   pub fn set_storage_path(&self, path: &[u16],
-      persist_session_cookies: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+      persist_session_cookies: libc::c_int,
+      callback: interfaces::CefCompletionCallback) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -330,18 +358,20 @@ impl CefCookieManager {
         ((*self.c_object).set_storage_path.unwrap())(
           self.c_object,
           CefWrap::to_c(path),
-          CefWrap::to_c(persist_session_cookies)))
+          CefWrap::to_c(persist_session_cookies),
+          CefWrap::to_c(callback)))
     }
   }
 
   //
-  // Flush the backing store (if any) to disk and execute the specified
-  // |callback| on the IO thread when done. Returns false (0) if cookies cannot
-  // be accessed.
+  // Flush the backing store (if any) to disk. If |callback| is non-NULL it will
+  // be executed asnychronously on the IO thread after the flush is complete.
+  // Returns false (0) if cookies cannot be accessed.
   //
   pub fn flush_store(&self,
       callback: interfaces::CefCompletionCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -354,13 +384,18 @@ impl CefCookieManager {
 
   //
   // Returns the global cookie manager. By default data will be stored at
-  // CefSettings.cache_path if specified or in memory otherwise.
+  // CefSettings.cache_path if specified or in memory otherwise. If |callback|
+  // is non-NULL it will be executed asnychronously on the IO thread after the
+  // manager's storage has been initialized. Using this function is equivalent
+  // to calling cef_request_tContext::cef_request_context_get_global_context()->
+  // get_default_cookie_manager().
   //
-  pub fn get_global_manager() -> interfaces::CefCookieManager {
+  pub fn get_global_manager(
+      callback: interfaces::CefCompletionCallback) -> interfaces::CefCookieManager {
     unsafe {
       CefWrap::to_rust(
         ::cookie::cef_cookie_manager_get_global_manager(
-))
+          CefWrap::to_c(callback)))
     }
   }
 
@@ -370,15 +405,17 @@ impl CefCookieManager {
   // persist session cookies (cookies without an expiry date or validity
   // interval) set |persist_session_cookies| to true (1). Session cookies are
   // generally intended to be transient and most Web browsers do not persist
-  // them. Returns NULL if creation fails.
+  // them. If |callback| is non-NULL it will be executed asnychronously on the
+  // IO thread after the manager's storage has been initialized.
   //
-  pub fn create_manager(path: &[u16],
-      persist_session_cookies: libc::c_int) -> interfaces::CefCookieManager {
+  pub fn create_manager(path: &[u16], persist_session_cookies: libc::c_int,
+      callback: interfaces::CefCompletionCallback) -> interfaces::CefCookieManager {
     unsafe {
       CefWrap::to_rust(
         ::cookie::cef_cookie_manager_create_manager(
           CefWrap::to_c(path),
-          CefWrap::to_c(persist_session_cookies)))
+          CefWrap::to_c(persist_session_cookies),
+          CefWrap::to_c(callback)))
     }
   }
 } 
@@ -399,7 +436,8 @@ impl CefWrap<*mut cef_cookie_manager_t> for Option<CefCookieManager> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_cookie_manager_t) -> Option<CefCookieManager> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefCookieManager::from_c_object_addref(c_object))
@@ -433,13 +471,13 @@ pub struct _cef_cookie_visitor_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_cookie_visitor_t = _cef_cookie_visitor_t;
 
@@ -455,7 +493,8 @@ pub struct CefCookieVisitor {
 impl Clone for CefCookieVisitor {
   fn clone(&self) -> CefCookieVisitor{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCookieVisitor {
@@ -468,7 +507,8 @@ impl Clone for CefCookieVisitor {
 impl Drop for CefCookieVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -483,7 +523,8 @@ impl CefCookieVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_cookie_visitor_t) -> CefCookieVisitor {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCookieVisitor {
@@ -497,7 +538,8 @@ impl CefCookieVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_cookie_visitor_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -505,10 +547,10 @@ impl CefCookieVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -520,7 +562,8 @@ impl CefCookieVisitor {
   //
   pub fn visit(&self, cookie: &interfaces::CefCookie, count: libc::c_int,
       total: libc::c_int, deleteCookie: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -551,7 +594,8 @@ impl CefWrap<*mut cef_cookie_visitor_t> for Option<CefCookieVisitor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_cookie_visitor_t) -> Option<CefCookieVisitor> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefCookieVisitor::from_c_object_addref(c_object))
@@ -559,3 +603,298 @@ impl CefWrap<*mut cef_cookie_visitor_t> for Option<CefCookieVisitor> {
   }
 }
 
+
+//
+// Structure to implement to be notified of asynchronous completion via
+// cef_cookie_manager_t::set_cookie().
+//
+#[repr(C)]
+pub struct _cef_set_cookie_callback_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Method that will be called upon completion. |success| will be true (1) if
+  // the cookie was set successfully.
+  //
+  pub on_complete: Option<extern "C" fn(this: *mut cef_set_cookie_callback_t,
+      success: libc::c_int) -> ()>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_set_cookie_callback_t = _cef_set_cookie_callback_t;
+
+
+//
+// Structure to implement to be notified of asynchronous completion via
+// cef_cookie_manager_t::set_cookie().
+//
+pub struct CefSetCookieCallback {
+  c_object: *mut cef_set_cookie_callback_t,
+}
+
+impl Clone for CefSetCookieCallback {
+  fn clone(&self) -> CefSetCookieCallback{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefSetCookieCallback {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefSetCookieCallback {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefSetCookieCallback {
+  pub unsafe fn from_c_object(c_object: *mut cef_set_cookie_callback_t) -> CefSetCookieCallback {
+    CefSetCookieCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_set_cookie_callback_t) -> CefSetCookieCallback {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefSetCookieCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_set_cookie_callback_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_set_cookie_callback_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Method that will be called upon completion. |success| will be true (1) if
+  // the cookie was set successfully.
+  //
+  pub fn on_complete(&self, success: libc::c_int) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_complete.unwrap())(
+          self.c_object,
+          CefWrap::to_c(success)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_set_cookie_callback_t> for CefSetCookieCallback {
+  fn to_c(rust_object: CefSetCookieCallback) -> *mut cef_set_cookie_callback_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_set_cookie_callback_t) -> CefSetCookieCallback {
+    CefSetCookieCallback::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_set_cookie_callback_t> for Option<CefSetCookieCallback> {
+  fn to_c(rust_object: Option<CefSetCookieCallback>) -> *mut cef_set_cookie_callback_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_set_cookie_callback_t) -> Option<CefSetCookieCallback> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefSetCookieCallback::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
+//
+// Structure to implement to be notified of asynchronous completion via
+// cef_cookie_manager_t::delete_cookies().
+//
+#[repr(C)]
+pub struct _cef_delete_cookies_callback_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Method that will be called upon completion. |num_deleted| will be the
+  // number of cookies that were deleted or -1 if unknown.
+  //
+  pub on_complete: Option<extern "C" fn(
+      this: *mut cef_delete_cookies_callback_t, num_deleted: libc::c_int) -> (
+      )>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_delete_cookies_callback_t = _cef_delete_cookies_callback_t;
+
+
+//
+// Structure to implement to be notified of asynchronous completion via
+// cef_cookie_manager_t::delete_cookies().
+//
+pub struct CefDeleteCookiesCallback {
+  c_object: *mut cef_delete_cookies_callback_t,
+}
+
+impl Clone for CefDeleteCookiesCallback {
+  fn clone(&self) -> CefDeleteCookiesCallback{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefDeleteCookiesCallback {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefDeleteCookiesCallback {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefDeleteCookiesCallback {
+  pub unsafe fn from_c_object(c_object: *mut cef_delete_cookies_callback_t) -> CefDeleteCookiesCallback {
+    CefDeleteCookiesCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_delete_cookies_callback_t) -> CefDeleteCookiesCallback {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefDeleteCookiesCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_delete_cookies_callback_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_delete_cookies_callback_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Method that will be called upon completion. |num_deleted| will be the
+  // number of cookies that were deleted or -1 if unknown.
+  //
+  pub fn on_complete(&self, num_deleted: libc::c_int) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_complete.unwrap())(
+          self.c_object,
+          CefWrap::to_c(num_deleted)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_delete_cookies_callback_t> for CefDeleteCookiesCallback {
+  fn to_c(rust_object: CefDeleteCookiesCallback) -> *mut cef_delete_cookies_callback_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_delete_cookies_callback_t) -> CefDeleteCookiesCallback {
+    CefDeleteCookiesCallback::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_delete_cookies_callback_t> for Option<CefDeleteCookiesCallback> {
+  fn to_c(rust_object: Option<CefDeleteCookiesCallback>) -> *mut cef_delete_cookies_callback_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_delete_cookies_callback_t) -> Option<CefDeleteCookiesCallback> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefDeleteCookiesCallback::from_c_object_addref(c_object))
+    }
+  }
+}
+
diff --git a/servo/ports/cef/interfaces/cef_dialog_handler.rs b/servo/ports/cef/interfaces/cef_dialog_handler.rs
index 029ecf9c3a03..c64634e061e8 100644
--- a/servo/ports/cef/interfaces/cef_dialog_handler.rs
+++ b/servo/ports/cef/interfaces/cef_dialog_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -56,11 +57,14 @@ pub struct _cef_file_dialog_callback_t {
   pub base: types::cef_base_t,
 
   //
-  // Continue the file selection with the specified |file_paths|. This may be a
-  // single value or a list of values depending on the dialog mode. An NULL
+  // Continue the file selection. |selected_accept_filter| should be the 0-based
+  // index of the value selected from the accept filters array passed to
+  // cef_dialog_handler_t::OnFileDialog. |file_paths| should be a single value
+  // or a list of values depending on the dialog mode. An NULL |file_paths|
   // value is treated the same as calling cancel().
   //
   pub cont: Option<extern "C" fn(this: *mut cef_file_dialog_callback_t,
+      selected_accept_filter: libc::c_int,
       file_paths: types::cef_string_list_t) -> ()>,
 
   //
@@ -72,13 +76,13 @@ pub struct _cef_file_dialog_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_file_dialog_callback_t = _cef_file_dialog_callback_t;
 
@@ -93,7 +97,8 @@ pub struct CefFileDialogCallback {
 impl Clone for CefFileDialogCallback {
   fn clone(&self) -> CefFileDialogCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFileDialogCallback {
@@ -106,7 +111,8 @@ impl Clone for CefFileDialogCallback {
 impl Drop for CefFileDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -121,7 +127,8 @@ impl CefFileDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_file_dialog_callback_t) -> CefFileDialogCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFileDialogCallback {
@@ -135,7 +142,8 @@ impl CefFileDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_file_dialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -143,25 +151,30 @@ impl CefFileDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Continue the file selection with the specified |file_paths|. This may be a
-  // single value or a list of values depending on the dialog mode. An NULL
+  // Continue the file selection. |selected_accept_filter| should be the 0-based
+  // index of the value selected from the accept filters array passed to
+  // cef_dialog_handler_t::OnFileDialog. |file_paths| should be a single value
+  // or a list of values depending on the dialog mode. An NULL |file_paths|
   // value is treated the same as calling cancel().
   //
-  pub fn cont(&self, file_paths: Vec<String>) -> () {
-    if self.c_object.is_null() {
+  pub fn cont(&self, selected_accept_filter: libc::c_int,
+      file_paths: Vec<String>) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
       CefWrap::to_rust(
         ((*self.c_object).cont.unwrap())(
           self.c_object,
+          CefWrap::to_c(selected_accept_filter),
           CefWrap::to_c(file_paths)))
     }
   }
@@ -170,7 +183,8 @@ impl CefFileDialogCallback {
   // Cancel the file selection.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -197,7 +211,8 @@ impl CefWrap<*mut cef_file_dialog_callback_t> for Option<CefFileDialogCallback>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_file_dialog_callback_t) -> Option<CefFileDialogCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefFileDialogCallback::from_c_object_addref(c_object))
@@ -221,30 +236,35 @@ pub struct _cef_dialog_handler_t {
   // Called to run a file chooser dialog. |mode| represents the type of dialog
   // to display. |title| to the title to be used for the dialog and may be NULL
   // to show the default title ("Open" or "Save" depending on the mode).
-  // |default_file_name| is the default file name to select in the dialog.
-  // |accept_types| is a list of valid lower-cased MIME types or file extensions
-  // specified in an input element and is used to restrict selectable files to
-  // such types. To display a custom dialog return true (1) and execute
-  // |callback| either inline or at a later time. To display the default dialog
-  // return false (0).
+  // |default_file_path| is the path with optional directory and/or file name
+  // component that should be initially selected in the dialog. |accept_filters|
+  // are used to restrict the selectable file types and may any combination of
+  // (a) valid lower-cased MIME types (e.g. "text/*" or "image/*"), (b)
+  // individual file extensions (e.g. ".txt" or ".png"), or (c) combined
+  // description and file extension delimited using "|" and ";" (e.g. "Image
+  // Types|.png;.gif;.jpg"). |selected_accept_filter| is the 0-based index of
+  // the filter that should be selected by default. To display a custom dialog
+  // return true (1) and execute |callback| either inline or at a later time. To
+  // display the default dialog return false (0).
   //
   pub on_file_dialog: Option<extern "C" fn(this: *mut cef_dialog_handler_t,
       browser: *mut interfaces::cef_browser_t,
       mode: types::cef_file_dialog_mode_t, title: *const types::cef_string_t,
-      default_file_name: *const types::cef_string_t,
-      accept_types: types::cef_string_list_t,
+      default_file_path: *const types::cef_string_t,
+      accept_filters: types::cef_string_list_t,
+      selected_accept_filter: libc::c_int,
       callback: *mut interfaces::cef_file_dialog_callback_t) -> libc::c_int>,
 
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_dialog_handler_t = _cef_dialog_handler_t;
 
@@ -260,7 +280,8 @@ pub struct CefDialogHandler {
 impl Clone for CefDialogHandler {
   fn clone(&self) -> CefDialogHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDialogHandler {
@@ -273,7 +294,8 @@ impl Clone for CefDialogHandler {
 impl Drop for CefDialogHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -288,7 +310,8 @@ impl CefDialogHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_dialog_handler_t) -> CefDialogHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDialogHandler {
@@ -302,7 +325,8 @@ impl CefDialogHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_dialog_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -310,28 +334,34 @@ impl CefDialogHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Called to run a file chooser dialog. |mode| represents the type of dialog
   // to display. |title| to the title to be used for the dialog and may be NULL
   // to show the default title ("Open" or "Save" depending on the mode).
-  // |default_file_name| is the default file name to select in the dialog.
-  // |accept_types| is a list of valid lower-cased MIME types or file extensions
-  // specified in an input element and is used to restrict selectable files to
-  // such types. To display a custom dialog return true (1) and execute
-  // |callback| either inline or at a later time. To display the default dialog
-  // return false (0).
+  // |default_file_path| is the path with optional directory and/or file name
+  // component that should be initially selected in the dialog. |accept_filters|
+  // are used to restrict the selectable file types and may any combination of
+  // (a) valid lower-cased MIME types (e.g. "text/*" or "image/*"), (b)
+  // individual file extensions (e.g. ".txt" or ".png"), or (c) combined
+  // description and file extension delimited using "|" and ";" (e.g. "Image
+  // Types|.png;.gif;.jpg"). |selected_accept_filter| is the 0-based index of
+  // the filter that should be selected by default. To display a custom dialog
+  // return true (1) and execute |callback| either inline or at a later time. To
+  // display the default dialog return false (0).
   //
   pub fn on_file_dialog(&self, browser: interfaces::CefBrowser,
       mode: types::cef_file_dialog_mode_t, title: &[u16],
-      default_file_name: &[u16], accept_types: Vec<String>,
+      default_file_path: &[u16], accept_filters: Vec<String>,
+      selected_accept_filter: libc::c_int,
       callback: interfaces::CefFileDialogCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -341,8 +371,9 @@ impl CefDialogHandler {
           CefWrap::to_c(browser),
           CefWrap::to_c(mode),
           CefWrap::to_c(title),
-          CefWrap::to_c(default_file_name),
-          CefWrap::to_c(accept_types),
+          CefWrap::to_c(default_file_path),
+          CefWrap::to_c(accept_filters),
+          CefWrap::to_c(selected_accept_filter),
           CefWrap::to_c(callback)))
     }
   }
@@ -364,7 +395,8 @@ impl CefWrap<*mut cef_dialog_handler_t> for Option<CefDialogHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_dialog_handler_t) -> Option<CefDialogHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDialogHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_display_handler.rs b/servo/ports/cef/interfaces/cef_display_handler.rs
index 4d90e2af6c00..1221e0e38890 100644
--- a/servo/ports/cef/interfaces/cef_display_handler.rs
+++ b/servo/ports/cef/interfaces/cef_display_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -71,6 +72,13 @@ pub struct _cef_display_handler_t {
       browser: *mut interfaces::cef_browser_t,
       title: *const types::cef_string_t) -> ()>,
 
+  //
+  // Called when the page icon changes.
+  //
+  pub on_favicon_urlchange: Option<extern "C" fn(
+      this: *mut cef_display_handler_t, browser: *mut interfaces::cef_browser_t,
+      icon_urls: types::cef_string_list_t) -> ()>,
+
   //
   // Called when the browser is about to display a tooltip. |text| contains the
   // text that will be displayed in the tooltip. To handle the display of the
@@ -103,13 +111,13 @@ pub struct _cef_display_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_display_handler_t = _cef_display_handler_t;
 
@@ -125,7 +133,8 @@ pub struct CefDisplayHandler {
 impl Clone for CefDisplayHandler {
   fn clone(&self) -> CefDisplayHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDisplayHandler {
@@ -138,7 +147,8 @@ impl Clone for CefDisplayHandler {
 impl Drop for CefDisplayHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -153,7 +163,8 @@ impl CefDisplayHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_display_handler_t) -> CefDisplayHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDisplayHandler {
@@ -167,7 +178,8 @@ impl CefDisplayHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_display_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -175,10 +187,10 @@ impl CefDisplayHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -186,7 +198,8 @@ impl CefDisplayHandler {
   //
   pub fn on_address_change(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -204,7 +217,8 @@ impl CefDisplayHandler {
   //
   pub fn on_title_change(&self, browser: interfaces::CefBrowser,
       title: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -216,6 +230,24 @@ impl CefDisplayHandler {
     }
   }
 
+  //
+  // Called when the page icon changes.
+  //
+  pub fn on_favicon_urlchange(&self, browser: interfaces::CefBrowser,
+      icon_urls: Vec<String>) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_favicon_urlchange.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser),
+          CefWrap::to_c(icon_urls)))
+    }
+  }
+
   //
   // Called when the browser is about to display a tooltip. |text| contains the
   // text that will be displayed in the tooltip. To handle the display of the
@@ -226,7 +258,8 @@ impl CefDisplayHandler {
   //
   pub fn on_tooltip(&self, browser: interfaces::CefBrowser,
       text: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -244,7 +277,8 @@ impl CefDisplayHandler {
   //
   pub fn on_status_message(&self, browser: interfaces::CefBrowser,
       value: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -262,7 +296,8 @@ impl CefDisplayHandler {
   //
   pub fn on_console_message(&self, browser: interfaces::CefBrowser,
       message: &[u16], source: &[u16], line: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -293,7 +328,8 @@ impl CefWrap<*mut cef_display_handler_t> for Option<CefDisplayHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_display_handler_t) -> Option<CefDisplayHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDisplayHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_dom.rs b/servo/ports/cef/interfaces/cef_dom.rs
index fc053c3bcf96..6fc2f880675e 100644
--- a/servo/ports/cef/interfaces/cef_dom.rs
+++ b/servo/ports/cef/interfaces/cef_dom.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -69,13 +70,13 @@ pub struct _cef_domvisitor_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_domvisitor_t = _cef_domvisitor_t;
 
@@ -91,7 +92,8 @@ pub struct CefDOMVisitor {
 impl Clone for CefDOMVisitor {
   fn clone(&self) -> CefDOMVisitor{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDOMVisitor {
@@ -104,7 +106,8 @@ impl Clone for CefDOMVisitor {
 impl Drop for CefDOMVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -119,7 +122,8 @@ impl CefDOMVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_domvisitor_t) -> CefDOMVisitor {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDOMVisitor {
@@ -133,7 +137,8 @@ impl CefDOMVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_domvisitor_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -141,10 +146,10 @@ impl CefDOMVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -155,7 +160,8 @@ impl CefDOMVisitor {
   // of this function.
   //
   pub fn visit(&self, document: interfaces::CefDOMDocument) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -183,7 +189,8 @@ impl CefWrap<*mut cef_domvisitor_t> for Option<CefDOMVisitor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_domvisitor_t) -> Option<CefDOMVisitor> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDOMVisitor::from_c_object_addref(c_object))
@@ -252,24 +259,12 @@ pub struct _cef_domdocument_t {
   pub has_selection: Option<extern "C" fn(
       this: *mut cef_domdocument_t) -> libc::c_int>,
 
-  //
-  // Returns the selection start node.
-  //
-  pub get_selection_start_node: Option<extern "C" fn(
-      this: *mut cef_domdocument_t) -> *mut interfaces::cef_domnode_t>,
-
   //
   // Returns the selection offset within the start node.
   //
   pub get_selection_start_offset: Option<extern "C" fn(
       this: *mut cef_domdocument_t) -> libc::c_int>,
 
-  //
-  // Returns the selection end node.
-  //
-  pub get_selection_end_node: Option<extern "C" fn(
-      this: *mut cef_domdocument_t) -> *mut interfaces::cef_domnode_t>,
-
   //
   // Returns the selection offset within the end node.
   //
@@ -308,13 +303,13 @@ pub struct _cef_domdocument_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_domdocument_t = _cef_domdocument_t;
 
@@ -330,7 +325,8 @@ pub struct CefDOMDocument {
 impl Clone for CefDOMDocument {
   fn clone(&self) -> CefDOMDocument{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDOMDocument {
@@ -343,7 +339,8 @@ impl Clone for CefDOMDocument {
 impl Drop for CefDOMDocument {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -358,7 +355,8 @@ impl CefDOMDocument {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_domdocument_t) -> CefDOMDocument {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDOMDocument {
@@ -372,7 +370,8 @@ impl CefDOMDocument {
 
   pub fn c_object_addrefed(&self) -> *mut cef_domdocument_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -380,17 +379,18 @@ impl CefDOMDocument {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns the document type.
   //
   pub fn get_type(&self) -> types::cef_dom_document_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -404,7 +404,8 @@ impl CefDOMDocument {
   // Returns the root document node.
   //
   pub fn get_document(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -418,7 +419,8 @@ impl CefDOMDocument {
   // Returns the BODY node of an HTML document.
   //
   pub fn get_body(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -432,7 +434,8 @@ impl CefDOMDocument {
   // Returns the HEAD node of an HTML document.
   //
   pub fn get_head(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -447,7 +450,8 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_title(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -461,7 +465,8 @@ impl CefDOMDocument {
   // Returns the document element with the specified ID value.
   //
   pub fn get_element_by_id(&self, id: &[u16]) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -476,7 +481,8 @@ impl CefDOMDocument {
   // Returns the node that currently has keyboard focus.
   //
   pub fn get_focused_node(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -490,7 +496,8 @@ impl CefDOMDocument {
   // Returns true (1) if a portion of the document is selected.
   //
   pub fn has_selection(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -500,25 +507,12 @@ impl CefDOMDocument {
     }
   }
 
-  //
-  // Returns the selection start node.
-  //
-  pub fn get_selection_start_node(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
-      panic!("called a CEF method on a null object")
-    }
-    unsafe {
-      CefWrap::to_rust(
-        ((*self.c_object).get_selection_start_node.unwrap())(
-          self.c_object))
-    }
-  }
-
   //
   // Returns the selection offset within the start node.
   //
   pub fn get_selection_start_offset(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -528,25 +522,12 @@ impl CefDOMDocument {
     }
   }
 
-  //
-  // Returns the selection end node.
-  //
-  pub fn get_selection_end_node(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
-      panic!("called a CEF method on a null object")
-    }
-    unsafe {
-      CefWrap::to_rust(
-        ((*self.c_object).get_selection_end_node.unwrap())(
-          self.c_object))
-    }
-  }
-
   //
   // Returns the selection offset within the end node.
   //
   pub fn get_selection_end_offset(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -561,7 +542,8 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_selection_as_markup(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -576,7 +558,8 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_selection_as_text(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -591,7 +574,8 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_base_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -607,7 +591,8 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_complete_url(&self, partialURL: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -635,7 +620,8 @@ impl CefWrap<*mut cef_domdocument_t> for Option<CefDOMDocument> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_domdocument_t) -> Option<CefDOMDocument> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDOMDocument::from_c_object_addref(c_object))
@@ -820,13 +806,13 @@ pub struct _cef_domnode_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_domnode_t = _cef_domnode_t;
 
@@ -842,7 +828,8 @@ pub struct CefDOMNode {
 impl Clone for CefDOMNode {
   fn clone(&self) -> CefDOMNode{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDOMNode {
@@ -855,7 +842,8 @@ impl Clone for CefDOMNode {
 impl Drop for CefDOMNode {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -870,7 +858,8 @@ impl CefDOMNode {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_domnode_t) -> CefDOMNode {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDOMNode {
@@ -884,7 +873,8 @@ impl CefDOMNode {
 
   pub fn c_object_addrefed(&self) -> *mut cef_domnode_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -892,17 +882,18 @@ impl CefDOMNode {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns the type for this node.
   //
   pub fn get_type(&self) -> types::cef_dom_node_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -916,7 +907,8 @@ impl CefDOMNode {
   // Returns true (1) if this is a text node.
   //
   pub fn is_text(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -930,7 +922,8 @@ impl CefDOMNode {
   // Returns true (1) if this is an element node.
   //
   pub fn is_element(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -944,7 +937,8 @@ impl CefDOMNode {
   // Returns true (1) if this is an editable node.
   //
   pub fn is_editable(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -958,7 +952,8 @@ impl CefDOMNode {
   // Returns true (1) if this is a form control element node.
   //
   pub fn is_form_control_element(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -973,7 +968,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_form_control_element_type(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -988,7 +984,8 @@ impl CefDOMNode {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefDOMNode) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1004,7 +1001,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1019,7 +1017,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_value(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1033,7 +1032,8 @@ impl CefDOMNode {
   // Set the value of this node. Returns true (1) on success.
   //
   pub fn set_value(&self, value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1049,7 +1049,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_as_markup(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1063,7 +1064,8 @@ impl CefDOMNode {
   // Returns the document associated with this node.
   //
   pub fn get_document(&self) -> interfaces::CefDOMDocument {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1077,7 +1079,8 @@ impl CefDOMNode {
   // Returns the parent node.
   //
   pub fn get_parent(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1091,7 +1094,8 @@ impl CefDOMNode {
   // Returns the previous sibling node.
   //
   pub fn get_previous_sibling(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1105,7 +1109,8 @@ impl CefDOMNode {
   // Returns the next sibling node.
   //
   pub fn get_next_sibling(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1119,7 +1124,8 @@ impl CefDOMNode {
   // Returns true (1) if this node has child nodes.
   //
   pub fn has_children(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1133,7 +1139,8 @@ impl CefDOMNode {
   // Return the first child node.
   //
   pub fn get_first_child(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1147,7 +1154,8 @@ impl CefDOMNode {
   // Returns the last child node.
   //
   pub fn get_last_child(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1165,7 +1173,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_element_tag_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1179,7 +1188,8 @@ impl CefDOMNode {
   // Returns true (1) if this element has attributes.
   //
   pub fn has_element_attributes(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1193,7 +1203,8 @@ impl CefDOMNode {
   // Returns true (1) if this element has an attribute named |attrName|.
   //
   pub fn has_element_attribute(&self, attrName: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1209,7 +1220,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_element_attribute(&self, attrName: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1224,7 +1236,8 @@ impl CefDOMNode {
   // Returns a map of all element attributes.
   //
   pub fn get_element_attributes(&self, attrMap: HashMap<String,String>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1241,7 +1254,8 @@ impl CefDOMNode {
   //
   pub fn set_element_attribute(&self, attrName: &[u16],
       value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1258,7 +1272,8 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_element_inner_text(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1285,7 +1300,8 @@ impl CefWrap<*mut cef_domnode_t> for Option<CefDOMNode> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_domnode_t) -> Option<CefDOMNode> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDOMNode::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_download_handler.rs b/servo/ports/cef/interfaces/cef_download_handler.rs
index 0757dfaf728d..7dce76b2ae0b 100644
--- a/servo/ports/cef/interfaces/cef_download_handler.rs
+++ b/servo/ports/cef/interfaces/cef_download_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -68,13 +69,13 @@ pub struct _cef_before_download_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_before_download_callback_t = _cef_before_download_callback_t;
 
@@ -89,7 +90,8 @@ pub struct CefBeforeDownloadCallback {
 impl Clone for CefBeforeDownloadCallback {
   fn clone(&self) -> CefBeforeDownloadCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBeforeDownloadCallback {
@@ -102,7 +104,8 @@ impl Clone for CefBeforeDownloadCallback {
 impl Drop for CefBeforeDownloadCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -117,7 +120,8 @@ impl CefBeforeDownloadCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_before_download_callback_t) -> CefBeforeDownloadCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBeforeDownloadCallback {
@@ -131,7 +135,8 @@ impl CefBeforeDownloadCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_before_download_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -139,10 +144,10 @@ impl CefBeforeDownloadCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -152,7 +157,8 @@ impl CefBeforeDownloadCallback {
   // (1) if you do wish to show the default "Save As" dialog.
   //
   pub fn cont(&self, download_path: &[u16], show_dialog: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -181,7 +187,8 @@ impl CefWrap<*mut cef_before_download_callback_t> for Option<CefBeforeDownloadCa
     }
   }
   unsafe fn to_rust(c_object: *mut cef_before_download_callback_t) -> Option<CefBeforeDownloadCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefBeforeDownloadCallback::from_c_object_addref(c_object))
@@ -206,16 +213,28 @@ pub struct _cef_download_item_callback_t {
   pub cancel: Option<extern "C" fn(this: *mut cef_download_item_callback_t) -> (
       )>,
 
+  //
+  // Call to pause the download.
+  //
+  pub pause: Option<extern "C" fn(this: *mut cef_download_item_callback_t) -> (
+      )>,
+
+  //
+  // Call to resume the download.
+  //
+  pub resume: Option<extern "C" fn(this: *mut cef_download_item_callback_t) -> (
+      )>,
+
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_download_item_callback_t = _cef_download_item_callback_t;
 
@@ -230,7 +249,8 @@ pub struct CefDownloadItemCallback {
 impl Clone for CefDownloadItemCallback {
   fn clone(&self) -> CefDownloadItemCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDownloadItemCallback {
@@ -243,7 +263,8 @@ impl Clone for CefDownloadItemCallback {
 impl Drop for CefDownloadItemCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -258,7 +279,8 @@ impl CefDownloadItemCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_download_item_callback_t) -> CefDownloadItemCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDownloadItemCallback {
@@ -272,7 +294,8 @@ impl CefDownloadItemCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_download_item_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -280,17 +303,18 @@ impl CefDownloadItemCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Call to cancel the download.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -299,6 +323,36 @@ impl CefDownloadItemCallback {
           self.c_object))
     }
   }
+
+  //
+  // Call to pause the download.
+  //
+  pub fn pause(&self) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).pause.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Call to resume the download.
+  //
+  pub fn resume(&self) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).resume.unwrap())(
+          self.c_object))
+    }
+  }
 } 
 
 impl CefWrap<*mut cef_download_item_callback_t> for CefDownloadItemCallback {
@@ -317,7 +371,8 @@ impl CefWrap<*mut cef_download_item_callback_t> for Option<CefDownloadItemCallba
     }
   }
   unsafe fn to_rust(c_object: *mut cef_download_item_callback_t) -> Option<CefDownloadItemCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDownloadItemCallback::from_c_object_addref(c_object))
@@ -367,13 +422,13 @@ pub struct _cef_download_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_download_handler_t = _cef_download_handler_t;
 
@@ -389,7 +444,8 @@ pub struct CefDownloadHandler {
 impl Clone for CefDownloadHandler {
   fn clone(&self) -> CefDownloadHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDownloadHandler {
@@ -402,7 +458,8 @@ impl Clone for CefDownloadHandler {
 impl Drop for CefDownloadHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -417,7 +474,8 @@ impl CefDownloadHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_download_handler_t) -> CefDownloadHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDownloadHandler {
@@ -431,7 +489,8 @@ impl CefDownloadHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_download_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -439,10 +498,10 @@ impl CefDownloadHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -455,7 +514,8 @@ impl CefDownloadHandler {
   pub fn on_before_download(&self, browser: interfaces::CefBrowser,
       download_item: interfaces::CefDownloadItem, suggested_name: &[u16],
       callback: interfaces::CefBeforeDownloadCallback) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -479,7 +539,8 @@ impl CefDownloadHandler {
   pub fn on_download_updated(&self, browser: interfaces::CefBrowser,
       download_item: interfaces::CefDownloadItem,
       callback: interfaces::CefDownloadItemCallback) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -509,7 +570,8 @@ impl CefWrap<*mut cef_download_handler_t> for Option<CefDownloadHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_download_handler_t) -> Option<CefDownloadHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDownloadHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_download_item.rs b/servo/ports/cef/interfaces/cef_download_item.rs
index 9fca39432842..88ca0fc16d9b 100644
--- a/servo/ports/cef/interfaces/cef_download_item.rs
+++ b/servo/ports/cef/interfaces/cef_download_item.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -136,6 +137,13 @@ pub struct _cef_download_item_t {
   pub get_url: Option<extern "C" fn(
       this: *mut cef_download_item_t) -> types::cef_string_userfree_t>,
 
+  //
+  // Returns the original URL before any redirections.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_original_url: Option<extern "C" fn(
+      this: *mut cef_download_item_t) -> types::cef_string_userfree_t>,
+
   //
   // Returns the suggested file name.
   //
@@ -160,13 +168,13 @@ pub struct _cef_download_item_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_download_item_t = _cef_download_item_t;
 
@@ -181,7 +189,8 @@ pub struct CefDownloadItem {
 impl Clone for CefDownloadItem {
   fn clone(&self) -> CefDownloadItem{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDownloadItem {
@@ -194,7 +203,8 @@ impl Clone for CefDownloadItem {
 impl Drop for CefDownloadItem {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -209,7 +219,8 @@ impl CefDownloadItem {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_download_item_t) -> CefDownloadItem {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDownloadItem {
@@ -223,7 +234,8 @@ impl CefDownloadItem {
 
   pub fn c_object_addrefed(&self) -> *mut cef_download_item_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -231,10 +243,10 @@ impl CefDownloadItem {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -242,7 +254,8 @@ impl CefDownloadItem {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -256,7 +269,8 @@ impl CefDownloadItem {
   // Returns true (1) if the download is in progress.
   //
   pub fn is_in_progress(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -270,7 +284,8 @@ impl CefDownloadItem {
   // Returns true (1) if the download is complete.
   //
   pub fn is_complete(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -284,7 +299,8 @@ impl CefDownloadItem {
   // Returns true (1) if the download has been canceled or interrupted.
   //
   pub fn is_canceled(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -298,7 +314,8 @@ impl CefDownloadItem {
   // Returns a simple speed estimate in bytes/s.
   //
   pub fn get_current_speed(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -313,7 +330,8 @@ impl CefDownloadItem {
   // unknown.
   //
   pub fn get_percent_complete(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -327,7 +345,8 @@ impl CefDownloadItem {
   // Returns the total number of bytes.
   //
   pub fn get_total_bytes(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -341,7 +360,8 @@ impl CefDownloadItem {
   // Returns the number of received bytes.
   //
   pub fn get_received_bytes(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -355,7 +375,8 @@ impl CefDownloadItem {
   // Returns the time that the download started.
   //
   pub fn get_start_time(&self) -> types::cef_time_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -369,7 +390,8 @@ impl CefDownloadItem {
   // Returns the time that the download ended.
   //
   pub fn get_end_time(&self) -> types::cef_time_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -384,7 +406,8 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_full_path(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -398,7 +421,8 @@ impl CefDownloadItem {
   // Returns the unique identifier for this download.
   //
   pub fn get_id(&self) -> u32 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -413,7 +437,8 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -423,12 +448,29 @@ impl CefDownloadItem {
     }
   }
 
+  //
+  // Returns the original URL before any redirections.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_original_url(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_original_url.unwrap())(
+          self.c_object))
+    }
+  }
+
   //
   // Returns the suggested file name.
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_suggested_file_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -443,7 +485,8 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_content_disposition(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -458,7 +501,8 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_mime_type(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -485,7 +529,8 @@ impl CefWrap<*mut cef_download_item_t> for Option<CefDownloadItem> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_download_item_t) -> Option<CefDownloadItem> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDownloadItem::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_drag_data.rs b/servo/ports/cef/interfaces/cef_drag_data.rs
index 599727db6dd7..2c4d3ec1349e 100644
--- a/servo/ports/cef/interfaces/cef_drag_data.rs
+++ b/servo/ports/cef/interfaces/cef_drag_data.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -204,13 +205,13 @@ pub struct _cef_drag_data_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_drag_data_t = _cef_drag_data_t;
 
@@ -226,7 +227,8 @@ pub struct CefDragData {
 impl Clone for CefDragData {
   fn clone(&self) -> CefDragData{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDragData {
@@ -239,7 +241,8 @@ impl Clone for CefDragData {
 impl Drop for CefDragData {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -254,7 +257,8 @@ impl CefDragData {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_drag_data_t) -> CefDragData {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDragData {
@@ -268,7 +272,8 @@ impl CefDragData {
 
   pub fn c_object_addrefed(&self) -> *mut cef_drag_data_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -276,17 +281,18 @@ impl CefDragData {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns a copy of the current object.
   //
   pub fn clone(&self) -> interfaces::CefDragData {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -300,7 +306,8 @@ impl CefDragData {
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -314,7 +321,8 @@ impl CefDragData {
   // Returns true (1) if the drag data is a link.
   //
   pub fn is_link(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -328,7 +336,8 @@ impl CefDragData {
   // Returns true (1) if the drag data is a text or html fragment.
   //
   pub fn is_fragment(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -342,7 +351,8 @@ impl CefDragData {
   // Returns true (1) if the drag data is a file.
   //
   pub fn is_file(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -357,7 +367,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -372,7 +383,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_title(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -387,7 +399,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_metadata(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -402,7 +415,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_fragment_text(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -417,7 +431,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_fragment_html(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -433,7 +448,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_fragment_base_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -448,7 +464,8 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_file_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -466,7 +483,8 @@ impl CefDragData {
   //
   pub fn get_file_contents(&self,
       writer: interfaces::CefStreamWriter) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -482,7 +500,8 @@ impl CefDragData {
   // window.
   //
   pub fn get_file_names(&self, names: Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -497,7 +516,8 @@ impl CefDragData {
   // Set the link URL that is being dragged.
   //
   pub fn set_link_url(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -512,7 +532,8 @@ impl CefDragData {
   // Set the title associated with the link being dragged.
   //
   pub fn set_link_title(&self, title: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -527,7 +548,8 @@ impl CefDragData {
   // Set the metadata associated with the link being dragged.
   //
   pub fn set_link_metadata(&self, data: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -542,7 +564,8 @@ impl CefDragData {
   // Set the plain text fragment that is being dragged.
   //
   pub fn set_fragment_text(&self, text: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -557,7 +580,8 @@ impl CefDragData {
   // Set the text/html fragment that is being dragged.
   //
   pub fn set_fragment_html(&self, html: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -572,7 +596,8 @@ impl CefDragData {
   // Set the base URL that the fragment came from.
   //
   pub fn set_fragment_base_url(&self, base_url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -589,7 +614,8 @@ impl CefDragData {
   // to drag in this kind of data.
   //
   pub fn reset_file_contents(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -603,7 +629,8 @@ impl CefDragData {
   // Add a file that is being dragged into the webview.
   //
   pub fn add_file(&self, path: &[u16], display_name: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -643,7 +670,8 @@ impl CefWrap<*mut cef_drag_data_t> for Option<CefDragData> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_drag_data_t) -> Option<CefDragData> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDragData::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_drag_handler.rs b/servo/ports/cef/interfaces/cef_drag_handler.rs
index 38dae28fefae..15fd7f37d8fd 100644
--- a/servo/ports/cef/interfaces/cef_drag_handler.rs
+++ b/servo/ports/cef/interfaces/cef_drag_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -70,13 +71,13 @@ pub struct _cef_drag_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_drag_handler_t = _cef_drag_handler_t;
 
@@ -92,7 +93,8 @@ pub struct CefDragHandler {
 impl Clone for CefDragHandler {
   fn clone(&self) -> CefDragHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDragHandler {
@@ -105,7 +107,8 @@ impl Clone for CefDragHandler {
 impl Drop for CefDragHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -120,7 +123,8 @@ impl CefDragHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_drag_handler_t) -> CefDragHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDragHandler {
@@ -134,7 +138,8 @@ impl CefDragHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_drag_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -142,10 +147,10 @@ impl CefDragHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -157,7 +162,8 @@ impl CefDragHandler {
   pub fn on_drag_enter(&self, browser: interfaces::CefBrowser,
       dragData: interfaces::CefDragData,
       mask: types::cef_drag_operations_mask_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -187,7 +193,8 @@ impl CefWrap<*mut cef_drag_handler_t> for Option<CefDragHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_drag_handler_t) -> Option<CefDragHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDragHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_find_handler.rs b/servo/ports/cef/interfaces/cef_find_handler.rs
new file mode 100644
index 000000000000..051550954512
--- /dev/null
+++ b/servo/ports/cef/interfaces/cef_find_handler.rs
@@ -0,0 +1,212 @@
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool and should not be edited
+// by hand. See the translator.README.txt file in the tools directory for
+// more information.
+//
+
+#![allow(non_snake_case, unused_imports)]
+
+use eutil;
+use interfaces;
+use types;
+use wrappers::CefWrap;
+
+use libc;
+use std::collections::HashMap;
+use std::mem;
+use std::ptr;
+
+//
+// Implement this structure to handle events related to find results. The
+// functions of this structure will be called on the UI thread.
+//
+#[repr(C)]
+pub struct _cef_find_handler_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Called to report find results returned by cef_browser_host_t::find().
+  // |identifer| is the identifier passed to find(), |count| is the number of
+  // matches currently identified, |selectionRect| is the location of where the
+  // match was found (in window coordinates), |activeMatchOrdinal| is the
+  // current position in the search results, and |finalUpdate| is true (1) if
+  // this is the last find notification.
+  //
+  pub on_find_result: Option<extern "C" fn(this: *mut cef_find_handler_t,
+      browser: *mut interfaces::cef_browser_t, identifier: libc::c_int,
+      count: libc::c_int, selectionRect: *const types::cef_rect_t,
+      activeMatchOrdinal: libc::c_int, finalUpdate: libc::c_int) -> ()>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_find_handler_t = _cef_find_handler_t;
+
+
+//
+// Implement this structure to handle events related to find results. The
+// functions of this structure will be called on the UI thread.
+//
+pub struct CefFindHandler {
+  c_object: *mut cef_find_handler_t,
+}
+
+impl Clone for CefFindHandler {
+  fn clone(&self) -> CefFindHandler{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefFindHandler {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefFindHandler {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefFindHandler {
+  pub unsafe fn from_c_object(c_object: *mut cef_find_handler_t) -> CefFindHandler {
+    CefFindHandler {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_find_handler_t) -> CefFindHandler {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefFindHandler {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_find_handler_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_find_handler_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Called to report find results returned by cef_browser_host_t::find().
+  // |identifer| is the identifier passed to find(), |count| is the number of
+  // matches currently identified, |selectionRect| is the location of where the
+  // match was found (in window coordinates), |activeMatchOrdinal| is the
+  // current position in the search results, and |finalUpdate| is true (1) if
+  // this is the last find notification.
+  //
+  pub fn on_find_result(&self, browser: interfaces::CefBrowser,
+      identifier: libc::c_int, count: libc::c_int,
+      selectionRect: &types::cef_rect_t, activeMatchOrdinal: libc::c_int,
+      finalUpdate: libc::c_int) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_find_result.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser),
+          CefWrap::to_c(identifier),
+          CefWrap::to_c(count),
+          CefWrap::to_c(selectionRect),
+          CefWrap::to_c(activeMatchOrdinal),
+          CefWrap::to_c(finalUpdate)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_find_handler_t> for CefFindHandler {
+  fn to_c(rust_object: CefFindHandler) -> *mut cef_find_handler_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_find_handler_t) -> CefFindHandler {
+    CefFindHandler::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_find_handler_t> for Option<CefFindHandler> {
+  fn to_c(rust_object: Option<CefFindHandler>) -> *mut cef_find_handler_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_find_handler_t) -> Option<CefFindHandler> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefFindHandler::from_c_object_addref(c_object))
+    }
+  }
+}
+
diff --git a/servo/ports/cef/interfaces/cef_focus_handler.rs b/servo/ports/cef/interfaces/cef_focus_handler.rs
index 5314ded7237b..b5d1d6072b02 100644
--- a/servo/ports/cef/interfaces/cef_focus_handler.rs
+++ b/servo/ports/cef/interfaces/cef_focus_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -83,13 +84,13 @@ pub struct _cef_focus_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_focus_handler_t = _cef_focus_handler_t;
 
@@ -105,7 +106,8 @@ pub struct CefFocusHandler {
 impl Clone for CefFocusHandler {
   fn clone(&self) -> CefFocusHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFocusHandler {
@@ -118,7 +120,8 @@ impl Clone for CefFocusHandler {
 impl Drop for CefFocusHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -133,7 +136,8 @@ impl CefFocusHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_focus_handler_t) -> CefFocusHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFocusHandler {
@@ -147,7 +151,8 @@ impl CefFocusHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_focus_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -155,10 +160,10 @@ impl CefFocusHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -169,7 +174,8 @@ impl CefFocusHandler {
   //
   pub fn on_take_focus(&self, browser: interfaces::CefBrowser,
       next: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -188,7 +194,8 @@ impl CefFocusHandler {
   //
   pub fn on_set_focus(&self, browser: interfaces::CefBrowser,
       source: types::cef_focus_source_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -204,7 +211,8 @@ impl CefFocusHandler {
   // Called when the browser component has received focus.
   //
   pub fn on_got_focus(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -232,7 +240,8 @@ impl CefWrap<*mut cef_focus_handler_t> for Option<CefFocusHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_focus_handler_t) -> Option<CefFocusHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefFocusHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_frame.rs b/servo/ports/cef/interfaces/cef_frame.rs
index f22a8b682576..62fa1bb8d0e9 100644
--- a/servo/ports/cef/interfaces/cef_frame.rs
+++ b/servo/ports/cef/interfaces/cef_frame.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -214,13 +215,13 @@ pub struct _cef_frame_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_frame_t = _cef_frame_t;
 
@@ -238,7 +239,8 @@ pub struct CefFrame {
 impl Clone for CefFrame {
   fn clone(&self) -> CefFrame{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFrame {
@@ -251,7 +253,8 @@ impl Clone for CefFrame {
 impl Drop for CefFrame {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -266,7 +269,8 @@ impl CefFrame {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_frame_t) -> CefFrame {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFrame {
@@ -280,7 +284,8 @@ impl CefFrame {
 
   pub fn c_object_addrefed(&self) -> *mut cef_frame_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -288,17 +293,18 @@ impl CefFrame {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // True if this object is currently attached to a valid frame.
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -312,7 +318,8 @@ impl CefFrame {
   // Execute undo in this frame.
   //
   pub fn undo(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -326,7 +333,8 @@ impl CefFrame {
   // Execute redo in this frame.
   //
   pub fn redo(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -340,7 +348,8 @@ impl CefFrame {
   // Execute cut in this frame.
   //
   pub fn cut(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -354,7 +363,8 @@ impl CefFrame {
   // Execute copy in this frame.
   //
   pub fn copy(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -368,7 +378,8 @@ impl CefFrame {
   // Execute paste in this frame.
   //
   pub fn paste(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -382,7 +393,8 @@ impl CefFrame {
   // Execute delete in this frame.
   //
   pub fn del(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -396,7 +408,8 @@ impl CefFrame {
   // Execute select all in this frame.
   //
   pub fn select_all(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -412,7 +425,8 @@ impl CefFrame {
   // browser process.
   //
   pub fn view_source(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -427,7 +441,8 @@ impl CefFrame {
   // visitor.
   //
   pub fn get_source(&self, visitor: interfaces::CefStringVisitor) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -443,7 +458,8 @@ impl CefFrame {
   // visitor.
   //
   pub fn get_text(&self, visitor: interfaces::CefStringVisitor) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -458,7 +474,8 @@ impl CefFrame {
   // Load the request represented by the |request| object.
   //
   pub fn load_request(&self, request: interfaces::CefRequest) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -473,7 +490,8 @@ impl CefFrame {
   // Load the specified |url|.
   //
   pub fn load_url(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -490,7 +508,8 @@ impl CefFrame {
   // link clicks and web security restrictions may not behave as expected.
   //
   pub fn load_string(&self, string_val: &[u16], url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -511,7 +530,8 @@ impl CefFrame {
   //
   pub fn execute_java_script(&self, code: &[u16], script_url: &[u16],
       start_line: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -528,7 +548,8 @@ impl CefFrame {
   // Returns true (1) if this is the main (top-level) frame.
   //
   pub fn is_main(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -542,7 +563,8 @@ impl CefFrame {
   // Returns true (1) if this is the focused frame.
   //
   pub fn is_focused(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -561,7 +583,8 @@ impl CefFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -575,7 +598,8 @@ impl CefFrame {
   // Returns the globally unique identifier for this frame.
   //
   pub fn get_identifier(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -590,7 +614,8 @@ impl CefFrame {
   // frame.
   //
   pub fn get_parent(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -605,7 +630,8 @@ impl CefFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -619,7 +645,8 @@ impl CefFrame {
   // Returns the browser that this frame belongs to.
   //
   pub fn get_browser(&self) -> interfaces::CefBrowser {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -634,7 +661,8 @@ impl CefFrame {
   // called from the render process.
   //
   pub fn get_v8context(&self) -> interfaces::CefV8Context {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -649,7 +677,8 @@ impl CefFrame {
   // process.
   //
   pub fn visit_dom(&self, visitor: interfaces::CefDOMVisitor) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -677,7 +706,8 @@ impl CefWrap<*mut cef_frame_t> for Option<CefFrame> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_frame_t) -> Option<CefFrame> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefFrame::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_geolocation.rs b/servo/ports/cef/interfaces/cef_geolocation.rs
index a2a07a3b862d..0b4b54a3daae 100644
--- a/servo/ports/cef/interfaces/cef_geolocation.rs
+++ b/servo/ports/cef/interfaces/cef_geolocation.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -67,13 +68,13 @@ pub struct _cef_get_geolocation_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_get_geolocation_callback_t = _cef_get_geolocation_callback_t;
 
@@ -89,7 +90,8 @@ pub struct CefGetGeolocationCallback {
 impl Clone for CefGetGeolocationCallback {
   fn clone(&self) -> CefGetGeolocationCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefGetGeolocationCallback {
@@ -102,7 +104,8 @@ impl Clone for CefGetGeolocationCallback {
 impl Drop for CefGetGeolocationCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -117,7 +120,8 @@ impl CefGetGeolocationCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_get_geolocation_callback_t) -> CefGetGeolocationCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefGetGeolocationCallback {
@@ -131,7 +135,8 @@ impl CefGetGeolocationCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_get_geolocation_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -139,10 +144,10 @@ impl CefGetGeolocationCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -151,7 +156,8 @@ impl CefGetGeolocationCallback {
   //
   pub fn on_location_update(&self, position: &interfaces::CefGeoposition) -> (
       ) {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -179,7 +185,8 @@ impl CefWrap<*mut cef_get_geolocation_callback_t> for Option<CefGetGeolocationCa
     }
   }
   unsafe fn to_rust(c_object: *mut cef_get_geolocation_callback_t) -> Option<CefGetGeolocationCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefGetGeolocationCallback::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_geolocation_handler.rs b/servo/ports/cef/interfaces/cef_geolocation_handler.rs
index 5e98e92e8b06..5214a245c51e 100644
--- a/servo/ports/cef/interfaces/cef_geolocation_handler.rs
+++ b/servo/ports/cef/interfaces/cef_geolocation_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -65,13 +66,13 @@ pub struct _cef_geolocation_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_geolocation_callback_t = _cef_geolocation_callback_t;
 
@@ -87,7 +88,8 @@ pub struct CefGeolocationCallback {
 impl Clone for CefGeolocationCallback {
   fn clone(&self) -> CefGeolocationCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefGeolocationCallback {
@@ -100,7 +102,8 @@ impl Clone for CefGeolocationCallback {
 impl Drop for CefGeolocationCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -115,7 +118,8 @@ impl CefGeolocationCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_geolocation_callback_t) -> CefGeolocationCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefGeolocationCallback {
@@ -129,7 +133,8 @@ impl CefGeolocationCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_geolocation_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -137,17 +142,18 @@ impl CefGeolocationCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Call to allow or deny geolocation access.
   //
   pub fn cont(&self, allow: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -175,7 +181,8 @@ impl CefWrap<*mut cef_geolocation_callback_t> for Option<CefGeolocationCallback>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_geolocation_callback_t) -> Option<CefGeolocationCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefGeolocationCallback::from_c_object_addref(c_object))
@@ -224,13 +231,13 @@ pub struct _cef_geolocation_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_geolocation_handler_t = _cef_geolocation_handler_t;
 
@@ -247,7 +254,8 @@ pub struct CefGeolocationHandler {
 impl Clone for CefGeolocationHandler {
   fn clone(&self) -> CefGeolocationHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefGeolocationHandler {
@@ -260,7 +268,8 @@ impl Clone for CefGeolocationHandler {
 impl Drop for CefGeolocationHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -275,7 +284,8 @@ impl CefGeolocationHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_geolocation_handler_t) -> CefGeolocationHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefGeolocationHandler {
@@ -289,7 +299,8 @@ impl CefGeolocationHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_geolocation_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -297,10 +308,10 @@ impl CefGeolocationHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -315,7 +326,8 @@ impl CefGeolocationHandler {
       browser: interfaces::CefBrowser, requesting_url: &[u16],
       request_id: libc::c_int,
       callback: interfaces::CefGeolocationCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -337,7 +349,8 @@ impl CefGeolocationHandler {
   pub fn on_cancel_geolocation_permission(&self,
       browser: interfaces::CefBrowser, requesting_url: &[u16],
       request_id: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -367,7 +380,8 @@ impl CefWrap<*mut cef_geolocation_handler_t> for Option<CefGeolocationHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_geolocation_handler_t) -> Option<CefGeolocationHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefGeolocationHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_jsdialog_handler.rs b/servo/ports/cef/interfaces/cef_jsdialog_handler.rs
index 4c03c07f5a31..bdb24eb6abb7 100644
--- a/servo/ports/cef/interfaces/cef_jsdialog_handler.rs
+++ b/servo/ports/cef/interfaces/cef_jsdialog_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -66,13 +67,13 @@ pub struct _cef_jsdialog_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_jsdialog_callback_t = _cef_jsdialog_callback_t;
 
@@ -88,7 +89,8 @@ pub struct CefJSDialogCallback {
 impl Clone for CefJSDialogCallback {
   fn clone(&self) -> CefJSDialogCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefJSDialogCallback {
@@ -101,7 +103,8 @@ impl Clone for CefJSDialogCallback {
 impl Drop for CefJSDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -116,7 +119,8 @@ impl CefJSDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_jsdialog_callback_t) -> CefJSDialogCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefJSDialogCallback {
@@ -130,7 +134,8 @@ impl CefJSDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_jsdialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -138,10 +143,10 @@ impl CefJSDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -149,7 +154,8 @@ impl CefJSDialogCallback {
   // was pressed. The |user_input| value should be specified for prompt dialogs.
   //
   pub fn cont(&self, success: libc::c_int, user_input: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -178,7 +184,8 @@ impl CefWrap<*mut cef_jsdialog_callback_t> for Option<CefJSDialogCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_jsdialog_callback_t) -> Option<CefJSDialogCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefJSDialogCallback::from_c_object_addref(c_object))
@@ -255,13 +262,13 @@ pub struct _cef_jsdialog_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_jsdialog_handler_t = _cef_jsdialog_handler_t;
 
@@ -277,7 +284,8 @@ pub struct CefJSDialogHandler {
 impl Clone for CefJSDialogHandler {
   fn clone(&self) -> CefJSDialogHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefJSDialogHandler {
@@ -290,7 +298,8 @@ impl Clone for CefJSDialogHandler {
 impl Drop for CefJSDialogHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -305,7 +314,8 @@ impl CefJSDialogHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_jsdialog_handler_t) -> CefJSDialogHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefJSDialogHandler {
@@ -319,7 +329,8 @@ impl CefJSDialogHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_jsdialog_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -327,10 +338,10 @@ impl CefJSDialogHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -353,7 +364,8 @@ impl CefJSDialogHandler {
       message_text: &[u16], default_prompt_text: &[u16],
       callback: interfaces::CefJSDialogCallback,
       suppress_message: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -382,7 +394,8 @@ impl CefJSDialogHandler {
   pub fn on_before_unload_dialog(&self, browser: interfaces::CefBrowser,
       message_text: &[u16], is_reload: libc::c_int,
       callback: interfaces::CefJSDialogCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -402,7 +415,8 @@ impl CefJSDialogHandler {
   // dialogs are currently pending.
   //
   pub fn on_reset_dialog_state(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -417,7 +431,8 @@ impl CefJSDialogHandler {
   // Called when the default implementation dialog is closed.
   //
   pub fn on_dialog_closed(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -445,7 +460,8 @@ impl CefWrap<*mut cef_jsdialog_handler_t> for Option<CefJSDialogHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_jsdialog_handler_t) -> Option<CefJSDialogHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefJSDialogHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_keyboard_handler.rs b/servo/ports/cef/interfaces/cef_keyboard_handler.rs
index dc347e9dd371..88cf4f2a02b6 100644
--- a/servo/ports/cef/interfaces/cef_keyboard_handler.rs
+++ b/servo/ports/cef/interfaces/cef_keyboard_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -81,13 +82,13 @@ pub struct _cef_keyboard_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_keyboard_handler_t = _cef_keyboard_handler_t;
 
@@ -103,7 +104,8 @@ pub struct CefKeyboardHandler {
 impl Clone for CefKeyboardHandler {
   fn clone(&self) -> CefKeyboardHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefKeyboardHandler {
@@ -116,7 +118,8 @@ impl Clone for CefKeyboardHandler {
 impl Drop for CefKeyboardHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -131,7 +134,8 @@ impl CefKeyboardHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_keyboard_handler_t) -> CefKeyboardHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefKeyboardHandler {
@@ -145,7 +149,8 @@ impl CefKeyboardHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_keyboard_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -153,10 +158,10 @@ impl CefKeyboardHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   // Called before a keyboard event is sent to the renderer. |event| contains
@@ -167,7 +172,8 @@ impl CefKeyboardHandler {
   pub fn on_pre_key_event(&self, browser: interfaces::CefBrowser,
       event: &interfaces::CefKeyEvent, os_event: types::cef_event_handle_t,
       is_keyboard_shortcut: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -190,7 +196,8 @@ impl CefKeyboardHandler {
   pub fn on_key_event(&self, browser: interfaces::CefBrowser,
       event: &interfaces::CefKeyEvent,
       os_event: types::cef_event_handle_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -220,7 +227,8 @@ impl CefWrap<*mut cef_keyboard_handler_t> for Option<CefKeyboardHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_keyboard_handler_t) -> Option<CefKeyboardHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefKeyboardHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_life_span_handler.rs b/servo/ports/cef/interfaces/cef_life_span_handler.rs
index 106ce028ae98..cf2da9488696 100644
--- a/servo/ports/cef/interfaces/cef_life_span_handler.rs
+++ b/servo/ports/cef/interfaces/cef_life_span_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -58,22 +59,29 @@ pub struct _cef_life_span_handler_t {
   pub base: types::cef_base_t,
 
   //
-  // Called on the IO thread before a new popup window is created. The |browser|
-  // and |frame| parameters represent the source of the popup request. The
-  // |target_url| and |target_frame_name| values may be NULL if none were
-  // specified with the request. The |popupFeatures| structure contains
-  // information about the requested popup window. To allow creation of the
-  // popup window optionally modify |windowInfo|, |client|, |settings| and
-  // |no_javascript_access| and return false (0). To cancel creation of the
-  // popup window return true (1). The |client| and |settings| values will
-  // default to the source browser's values. The |no_javascript_access| value
-  // indicates whether the new browser window should be scriptable and in the
-  // same process as the source browser.
+  // Called on the IO thread before a new popup browser is created. The
+  // |browser| and |frame| values represent the source of the popup request. The
+  // |target_url| and |target_frame_name| values indicate where the popup
+  // browser should navigate and may be NULL if not specified with the request.
+  // The |target_disposition| value indicates where the user intended to open
+  // the popup (e.g. current tab, new tab, etc). The |user_gesture| value will
+  // be true (1) if the popup was opened via explicit user gesture (e.g.
+  // clicking a link) or false (0) if the popup opened automatically (e.g. via
+  // the DomContentLoaded event). The |popupFeatures| structure contains
+  // additional information about the requested popup window. To allow creation
+  // of the popup browser optionally modify |windowInfo|, |client|, |settings|
+  // and |no_javascript_access| and return false (0). To cancel creation of the
+  // popup browser return true (1). The |client| and |settings| values will
+  // default to the source browser's values. If the |no_javascript_access| value
+  // is set to false (0) the new browser will not be scriptable and may not be
+  // hosted in the same renderer process as the source browser.
   pub on_before_popup: Option<extern "C" fn(this: *mut cef_life_span_handler_t,
       browser: *mut interfaces::cef_browser_t,
       frame: *mut interfaces::cef_frame_t,
       target_url: *const types::cef_string_t,
       target_frame_name: *const types::cef_string_t,
+      target_disposition: types::cef_window_open_disposition_t,
+      user_gesture: libc::c_int,
       popupFeatures: *const interfaces::cef_popup_features_t,
       windowInfo: *mut interfaces::cef_window_info_t,
       client: *mut interfaces::cef_client_t,
@@ -95,7 +103,7 @@ pub struct _cef_life_span_handler_t {
       browser: *mut interfaces::cef_browser_t) -> libc::c_int>,
 
   //
-  // Called when a browser has received a request to close. This may result
+  // Called when a browser has recieved a request to close. This may result
   // directly from a call to cef_browser_host_t::close_browser() or indirectly
   // if the browser is a top-level OS window created by CEF and the user
   // attempts to close the window. This function will be called after the
@@ -168,13 +176,13 @@ pub struct _cef_life_span_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_life_span_handler_t = _cef_life_span_handler_t;
 
@@ -191,7 +199,8 @@ pub struct CefLifeSpanHandler {
 impl Clone for CefLifeSpanHandler {
   fn clone(&self) -> CefLifeSpanHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefLifeSpanHandler {
@@ -204,7 +213,8 @@ impl Clone for CefLifeSpanHandler {
 impl Drop for CefLifeSpanHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -219,7 +229,8 @@ impl CefLifeSpanHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_life_span_handler_t) -> CefLifeSpanHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefLifeSpanHandler {
@@ -233,7 +244,8 @@ impl CefLifeSpanHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_life_span_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -241,32 +253,40 @@ impl CefLifeSpanHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Called on the IO thread before a new popup window is created. The |browser|
-  // and |frame| parameters represent the source of the popup request. The
-  // |target_url| and |target_frame_name| values may be NULL if none were
-  // specified with the request. The |popupFeatures| structure contains
-  // information about the requested popup window. To allow creation of the
-  // popup window optionally modify |windowInfo|, |client|, |settings| and
-  // |no_javascript_access| and return false (0). To cancel creation of the
-  // popup window return true (1). The |client| and |settings| values will
-  // default to the source browser's values. The |no_javascript_access| value
-  // indicates whether the new browser window should be scriptable and in the
-  // same process as the source browser.
+  // Called on the IO thread before a new popup browser is created. The
+  // |browser| and |frame| values represent the source of the popup request. The
+  // |target_url| and |target_frame_name| values indicate where the popup
+  // browser should navigate and may be NULL if not specified with the request.
+  // The |target_disposition| value indicates where the user intended to open
+  // the popup (e.g. current tab, new tab, etc). The |user_gesture| value will
+  // be true (1) if the popup was opened via explicit user gesture (e.g.
+  // clicking a link) or false (0) if the popup opened automatically (e.g. via
+  // the DomContentLoaded event). The |popupFeatures| structure contains
+  // additional information about the requested popup window. To allow creation
+  // of the popup browser optionally modify |windowInfo|, |client|, |settings|
+  // and |no_javascript_access| and return false (0). To cancel creation of the
+  // popup browser return true (1). The |client| and |settings| values will
+  // default to the source browser's values. If the |no_javascript_access| value
+  // is set to false (0) the new browser will not be scriptable and may not be
+  // hosted in the same renderer process as the source browser.
   pub fn on_before_popup(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, target_url: &[u16],
-      target_frame_name: &[u16], popupFeatures: &interfaces::CefPopupFeatures,
+      target_frame_name: &[u16],
+      target_disposition: types::cef_window_open_disposition_t,
+      user_gesture: libc::c_int, popupFeatures: &interfaces::CefPopupFeatures,
       windowInfo: &mut interfaces::CefWindowInfo,
       client: interfaces::CefClient,
       settings: &mut interfaces::CefBrowserSettings,
       no_javascript_access: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -277,6 +297,8 @@ impl CefLifeSpanHandler {
           CefWrap::to_c(frame),
           CefWrap::to_c(target_url),
           CefWrap::to_c(target_frame_name),
+          CefWrap::to_c(target_disposition),
+          CefWrap::to_c(user_gesture),
           CefWrap::to_c(popupFeatures),
           CefWrap::to_c(windowInfo),
           CefWrap::to_c(client),
@@ -289,7 +311,8 @@ impl CefLifeSpanHandler {
   // Called after a new browser is created.
   //
   pub fn on_after_created(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,7 +329,8 @@ impl CefLifeSpanHandler {
   // implementation or true (1) to use a custom implementation.
   //
   pub fn run_modal(&self, browser: interfaces::CefBrowser) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -318,7 +342,7 @@ impl CefLifeSpanHandler {
   }
 
   //
-  // Called when a browser has received a request to close. This may result
+  // Called when a browser has recieved a request to close. This may result
   // directly from a call to cef_browser_host_t::close_browser() or indirectly
   // if the browser is a top-level OS window created by CEF and the user
   // attempts to close the window. This function will be called after the
@@ -375,7 +399,8 @@ impl CefLifeSpanHandler {
   //     exist.
   //
   pub fn do_close(&self, browser: interfaces::CefBrowser) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -395,7 +420,8 @@ impl CefLifeSpanHandler {
   // additional usage information.
   //
   pub fn on_before_close(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -423,7 +449,8 @@ impl CefWrap<*mut cef_life_span_handler_t> for Option<CefLifeSpanHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_life_span_handler_t) -> Option<CefLifeSpanHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefLifeSpanHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_load_handler.rs b/servo/ports/cef/interfaces/cef_load_handler.rs
index e242dc23fa3c..d18a0ec39306 100644
--- a/servo/ports/cef/interfaces/cef_load_handler.rs
+++ b/servo/ports/cef/interfaces/cef_load_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -108,13 +109,13 @@ pub struct _cef_load_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_load_handler_t = _cef_load_handler_t;
 
@@ -131,7 +132,8 @@ pub struct CefLoadHandler {
 impl Clone for CefLoadHandler {
   fn clone(&self) -> CefLoadHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefLoadHandler {
@@ -144,7 +146,8 @@ impl Clone for CefLoadHandler {
 impl Drop for CefLoadHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -159,7 +162,8 @@ impl CefLoadHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_load_handler_t) -> CefLoadHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefLoadHandler {
@@ -173,7 +177,8 @@ impl CefLoadHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_load_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -181,10 +186,10 @@ impl CefLoadHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -196,7 +201,8 @@ impl CefLoadHandler {
   pub fn on_loading_state_change(&self, browser: interfaces::CefBrowser,
       isLoading: libc::c_int, canGoBack: libc::c_int,
       canGoForward: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -221,7 +227,8 @@ impl CefLoadHandler {
   //
   pub fn on_load_start(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -243,7 +250,8 @@ impl CefLoadHandler {
   //
   pub fn on_load_end(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, httpStatusCode: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -265,7 +273,8 @@ impl CefLoadHandler {
   pub fn on_load_error(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, errorCode: types::cef_errorcode_t,
       errorText: &[u16], failedUrl: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -297,7 +306,8 @@ impl CefWrap<*mut cef_load_handler_t> for Option<CefLoadHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_load_handler_t) -> Option<CefLoadHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefLoadHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_menu_model.rs b/servo/ports/cef/interfaces/cef_menu_model.rs
index 6f3df5a486c3..2c686f475762 100644
--- a/servo/ports/cef/interfaces/cef_menu_model.rs
+++ b/servo/ports/cef/interfaces/cef_menu_model.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -401,13 +402,13 @@ pub struct _cef_menu_model_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_menu_model_t = _cef_menu_model_t;
 
@@ -425,7 +426,8 @@ pub struct CefMenuModel {
 impl Clone for CefMenuModel {
   fn clone(&self) -> CefMenuModel{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefMenuModel {
@@ -438,7 +440,8 @@ impl Clone for CefMenuModel {
 impl Drop for CefMenuModel {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -453,7 +456,8 @@ impl CefMenuModel {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_menu_model_t) -> CefMenuModel {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefMenuModel {
@@ -467,7 +471,8 @@ impl CefMenuModel {
 
   pub fn c_object_addrefed(&self) -> *mut cef_menu_model_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -475,17 +480,18 @@ impl CefMenuModel {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Clears the menu. Returns true (1) on success.
   //
   pub fn clear(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -499,7 +505,8 @@ impl CefMenuModel {
   // Returns the number of items in this menu.
   //
   pub fn get_count(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -513,7 +520,8 @@ impl CefMenuModel {
   // Add a separator to the menu. Returns true (1) on success.
   //
   pub fn add_separator(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -528,7 +536,8 @@ impl CefMenuModel {
   //
   pub fn add_item(&self, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -545,7 +554,8 @@ impl CefMenuModel {
   //
   pub fn add_check_item(&self, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -563,7 +573,8 @@ impl CefMenuModel {
   //
   pub fn add_radio_item(&self, command_id: libc::c_int, label: &[u16],
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -581,7 +592,8 @@ impl CefMenuModel {
   //
   pub fn add_sub_menu(&self, command_id: libc::c_int,
       label: &[u16]) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -598,7 +610,8 @@ impl CefMenuModel {
   // on success.
   //
   pub fn insert_separator_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -615,7 +628,8 @@ impl CefMenuModel {
   //
   pub fn insert_item_at(&self, index: libc::c_int, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -634,7 +648,8 @@ impl CefMenuModel {
   //
   pub fn insert_check_item_at(&self, index: libc::c_int,
       command_id: libc::c_int, label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -655,7 +670,8 @@ impl CefMenuModel {
   pub fn insert_radio_item_at(&self, index: libc::c_int,
       command_id: libc::c_int, label: &[u16],
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -675,7 +691,8 @@ impl CefMenuModel {
   //
   pub fn insert_sub_menu_at(&self, index: libc::c_int, command_id: libc::c_int,
       label: &[u16]) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -693,7 +710,8 @@ impl CefMenuModel {
   // success.
   //
   pub fn remove(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -708,7 +726,8 @@ impl CefMenuModel {
   // Removes the item at the specified |index|. Returns true (1) on success.
   //
   pub fn remove_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -724,7 +743,8 @@ impl CefMenuModel {
   // found due to the command id not existing in the menu.
   //
   pub fn get_index_of(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -740,7 +760,8 @@ impl CefMenuModel {
   // invalid range or the index being a separator.
   //
   pub fn get_command_id_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -756,7 +777,8 @@ impl CefMenuModel {
   //
   pub fn set_command_id_at(&self, index: libc::c_int,
       command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -773,7 +795,8 @@ impl CefMenuModel {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_label(&self, command_id: libc::c_int) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -790,7 +813,8 @@ impl CefMenuModel {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_label_at(&self, index: libc::c_int) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -806,7 +830,8 @@ impl CefMenuModel {
   //
   pub fn set_label(&self, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -822,7 +847,8 @@ impl CefMenuModel {
   // Set the label at the specified |index|. Returns true (1) on success.
   //
   pub fn set_label_at(&self, index: libc::c_int, label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -839,7 +865,8 @@ impl CefMenuModel {
   //
   pub fn get_type(&self,
       command_id: libc::c_int) -> types::cef_menu_item_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -854,7 +881,8 @@ impl CefMenuModel {
   // Returns the item type at the specified |index|.
   //
   pub fn get_type_at(&self, index: libc::c_int) -> types::cef_menu_item_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -869,7 +897,8 @@ impl CefMenuModel {
   // Returns the group id for the specified |command_id| or -1 if invalid.
   //
   pub fn get_group_id(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -884,7 +913,8 @@ impl CefMenuModel {
   // Returns the group id at the specified |index| or -1 if invalid.
   //
   pub fn get_group_id_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -901,7 +931,8 @@ impl CefMenuModel {
   //
   pub fn set_group_id(&self, command_id: libc::c_int,
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -918,7 +949,8 @@ impl CefMenuModel {
   //
   pub fn set_group_id_at(&self, index: libc::c_int,
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -935,7 +967,8 @@ impl CefMenuModel {
   //
   pub fn get_sub_menu(&self,
       command_id: libc::c_int) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -951,7 +984,8 @@ impl CefMenuModel {
   //
   pub fn get_sub_menu_at(&self,
       index: libc::c_int) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -966,7 +1000,8 @@ impl CefMenuModel {
   // Returns true (1) if the specified |command_id| is visible.
   //
   pub fn is_visible(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -981,7 +1016,8 @@ impl CefMenuModel {
   // Returns true (1) if the specified |index| is visible.
   //
   pub fn is_visible_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -998,7 +1034,8 @@ impl CefMenuModel {
   //
   pub fn set_visible(&self, command_id: libc::c_int,
       visible: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1016,7 +1053,8 @@ impl CefMenuModel {
   //
   pub fn set_visible_at(&self, index: libc::c_int,
       visible: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1032,7 +1070,8 @@ impl CefMenuModel {
   // Returns true (1) if the specified |command_id| is enabled.
   //
   pub fn is_enabled(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1047,7 +1086,8 @@ impl CefMenuModel {
   // Returns true (1) if the specified |index| is enabled.
   //
   pub fn is_enabled_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1064,7 +1104,8 @@ impl CefMenuModel {
   //
   pub fn set_enabled(&self, command_id: libc::c_int,
       enabled: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1082,7 +1123,8 @@ impl CefMenuModel {
   //
   pub fn set_enabled_at(&self, index: libc::c_int,
       enabled: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1099,7 +1141,8 @@ impl CefMenuModel {
   // check and radio items.
   //
   pub fn is_checked(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1115,7 +1158,8 @@ impl CefMenuModel {
   // and radio items.
   //
   pub fn is_checked_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1132,7 +1176,8 @@ impl CefMenuModel {
   //
   pub fn set_checked(&self, command_id: libc::c_int,
       checked: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1150,7 +1195,8 @@ impl CefMenuModel {
   //
   pub fn set_checked_at(&self, index: libc::c_int,
       checked: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1167,7 +1213,8 @@ impl CefMenuModel {
   // assigned.
   //
   pub fn has_accelerator(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1183,7 +1230,8 @@ impl CefMenuModel {
   // assigned.
   //
   pub fn has_accelerator_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1201,7 +1249,8 @@ impl CefMenuModel {
   pub fn set_accelerator(&self, command_id: libc::c_int, key_code: libc::c_int,
       shift_pressed: libc::c_int, ctrl_pressed: libc::c_int,
       alt_pressed: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1223,7 +1272,8 @@ impl CefMenuModel {
   pub fn set_accelerator_at(&self, index: libc::c_int, key_code: libc::c_int,
       shift_pressed: libc::c_int, ctrl_pressed: libc::c_int,
       alt_pressed: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1243,7 +1293,8 @@ impl CefMenuModel {
   // true (1) on success.
   //
   pub fn remove_accelerator(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1259,7 +1310,8 @@ impl CefMenuModel {
   // on success.
   //
   pub fn remove_accelerator_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1278,7 +1330,8 @@ impl CefMenuModel {
       key_code: &mut libc::c_int, shift_pressed: &mut libc::c_int,
       ctrl_pressed: &mut libc::c_int,
       alt_pressed: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1301,7 +1354,8 @@ impl CefMenuModel {
       key_code: &mut libc::c_int, shift_pressed: &mut libc::c_int,
       ctrl_pressed: &mut libc::c_int,
       alt_pressed: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1333,7 +1387,8 @@ impl CefWrap<*mut cef_menu_model_t> for Option<CefMenuModel> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_menu_model_t) -> Option<CefMenuModel> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefMenuModel::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_navigation_entry.rs b/servo/ports/cef/interfaces/cef_navigation_entry.rs
new file mode 100644
index 000000000000..6654b72cccb0
--- /dev/null
+++ b/servo/ports/cef/interfaces/cef_navigation_entry.rs
@@ -0,0 +1,404 @@
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool and should not be edited
+// by hand. See the translator.README.txt file in the tools directory for
+// more information.
+//
+
+#![allow(non_snake_case, unused_imports)]
+
+use eutil;
+use interfaces;
+use types;
+use wrappers::CefWrap;
+
+use libc;
+use std::collections::HashMap;
+use std::mem;
+use std::ptr;
+
+//
+// Structure used to represent an entry in navigation history.
+//
+#[repr(C)]
+pub struct _cef_navigation_entry_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Returns true (1) if this object is valid. Do not call any other functions
+  // if this function returns false (0).
+  //
+  pub is_valid: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> libc::c_int>,
+
+  //
+  // Returns the actual URL of the page. For some pages this may be data: URL or
+  // similar. Use get_display_url() to return a display-friendly version.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_url: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns a display-friendly version of the URL.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_display_url: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the original URL that was entered by the user before any redirects.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_original_url: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the title set by the page. This value may be NULL.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_title: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the transition type which indicates what the user did to move to
+  // this page from the previous page.
+  //
+  pub get_transition_type: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_transition_type_t>,
+
+  //
+  // Returns true (1) if this navigation includes post data.
+  //
+  pub has_post_data: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> libc::c_int>,
+
+  //
+  // Returns the name of the sub-frame that navigated or an NULL value if the
+  // main frame navigated.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_frame_name: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the time for the last known successful navigation completion. A
+  // navigation may be completed more than once if the page is reloaded. May be
+  // 0 if the navigation has not yet completed.
+  //
+  pub get_completion_time: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> types::cef_time_t>,
+
+  //
+  // Returns the HTTP status code for the last known successful navigation
+  // response. May be 0 if the response has not yet been received or if the
+  // navigation has not yet completed.
+  //
+  pub get_http_status_code: Option<extern "C" fn(
+      this: *mut cef_navigation_entry_t) -> libc::c_int>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_navigation_entry_t = _cef_navigation_entry_t;
+
+
+//
+// Structure used to represent an entry in navigation history.
+//
+pub struct CefNavigationEntry {
+  c_object: *mut cef_navigation_entry_t,
+}
+
+impl Clone for CefNavigationEntry {
+  fn clone(&self) -> CefNavigationEntry{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefNavigationEntry {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefNavigationEntry {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefNavigationEntry {
+  pub unsafe fn from_c_object(c_object: *mut cef_navigation_entry_t) -> CefNavigationEntry {
+    CefNavigationEntry {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_navigation_entry_t) -> CefNavigationEntry {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefNavigationEntry {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_navigation_entry_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_navigation_entry_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Returns true (1) if this object is valid. Do not call any other functions
+  // if this function returns false (0).
+  //
+  pub fn is_valid(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_valid.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the actual URL of the page. For some pages this may be data: URL or
+  // similar. Use get_display_url() to return a display-friendly version.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_url(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_url.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns a display-friendly version of the URL.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_display_url(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_display_url.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the original URL that was entered by the user before any redirects.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_original_url(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_original_url.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the title set by the page. This value may be NULL.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_title(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_title.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the transition type which indicates what the user did to move to
+  // this page from the previous page.
+  //
+  pub fn get_transition_type(&self) -> types::cef_transition_type_t {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_transition_type.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns true (1) if this navigation includes post data.
+  //
+  pub fn has_post_data(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).has_post_data.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the name of the sub-frame that navigated or an NULL value if the
+  // main frame navigated.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_frame_name(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_frame_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the time for the last known successful navigation completion. A
+  // navigation may be completed more than once if the page is reloaded. May be
+  // 0 if the navigation has not yet completed.
+  //
+  pub fn get_completion_time(&self) -> types::cef_time_t {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_completion_time.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the HTTP status code for the last known successful navigation
+  // response. May be 0 if the response has not yet been received or if the
+  // navigation has not yet completed.
+  //
+  pub fn get_http_status_code(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_http_status_code.unwrap())(
+          self.c_object))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_navigation_entry_t> for CefNavigationEntry {
+  fn to_c(rust_object: CefNavigationEntry) -> *mut cef_navigation_entry_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_navigation_entry_t) -> CefNavigationEntry {
+    CefNavigationEntry::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_navigation_entry_t> for Option<CefNavigationEntry> {
+  fn to_c(rust_object: Option<CefNavigationEntry>) -> *mut cef_navigation_entry_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_navigation_entry_t) -> Option<CefNavigationEntry> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefNavigationEntry::from_c_object_addref(c_object))
+    }
+  }
+}
+
diff --git a/servo/ports/cef/interfaces/cef_origin_whitelist.rs b/servo/ports/cef/interfaces/cef_origin_whitelist.rs
index c8622bc9cc9e..c396bf66e02e 100644
--- a/servo/ports/cef/interfaces/cef_origin_whitelist.rs
+++ b/servo/ports/cef/interfaces/cef_origin_whitelist.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,4 +43,5 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
diff --git a/servo/ports/cef/interfaces/cef_url.rs b/servo/ports/cef/interfaces/cef_parser.rs
similarity index 96%
rename from servo/ports/cef/interfaces/cef_url.rs
rename to servo/ports/cef/interfaces/cef_parser.rs
index c8622bc9cc9e..c396bf66e02e 100644
--- a/servo/ports/cef/interfaces/cef_url.rs
+++ b/servo/ports/cef/interfaces/cef_parser.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,4 +43,5 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
diff --git a/servo/ports/cef/interfaces/cef_path_util.rs b/servo/ports/cef/interfaces/cef_path_util.rs
index c8622bc9cc9e..c396bf66e02e 100644
--- a/servo/ports/cef/interfaces/cef_path_util.rs
+++ b/servo/ports/cef/interfaces/cef_path_util.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,4 +43,5 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
diff --git a/servo/ports/cef/interfaces/cef_print_handler.rs b/servo/ports/cef/interfaces/cef_print_handler.rs
index d5cabeae8dfb..9737d87a9a36 100644
--- a/servo/ports/cef/interfaces/cef_print_handler.rs
+++ b/servo/ports/cef/interfaces/cef_print_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -70,13 +71,13 @@ pub struct _cef_print_dialog_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_print_dialog_callback_t = _cef_print_dialog_callback_t;
 
@@ -91,7 +92,8 @@ pub struct CefPrintDialogCallback {
 impl Clone for CefPrintDialogCallback {
   fn clone(&self) -> CefPrintDialogCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintDialogCallback {
@@ -104,7 +106,8 @@ impl Clone for CefPrintDialogCallback {
 impl Drop for CefPrintDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -119,7 +122,8 @@ impl CefPrintDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_dialog_callback_t) -> CefPrintDialogCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintDialogCallback {
@@ -133,7 +137,8 @@ impl CefPrintDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_dialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -141,17 +146,18 @@ impl CefPrintDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Continue printing with the specified |settings|.
   //
   pub fn cont(&self, settings: interfaces::CefPrintSettings) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -166,7 +172,8 @@ impl CefPrintDialogCallback {
   // Cancel the printing.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -193,7 +200,8 @@ impl CefWrap<*mut cef_print_dialog_callback_t> for Option<CefPrintDialogCallback
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_dialog_callback_t) -> Option<CefPrintDialogCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefPrintDialogCallback::from_c_object_addref(c_object))
@@ -220,13 +228,13 @@ pub struct _cef_print_job_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_print_job_callback_t = _cef_print_job_callback_t;
 
@@ -241,7 +249,8 @@ pub struct CefPrintJobCallback {
 impl Clone for CefPrintJobCallback {
   fn clone(&self) -> CefPrintJobCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintJobCallback {
@@ -254,7 +263,8 @@ impl Clone for CefPrintJobCallback {
 impl Drop for CefPrintJobCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -269,7 +279,8 @@ impl CefPrintJobCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_job_callback_t) -> CefPrintJobCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintJobCallback {
@@ -283,7 +294,8 @@ impl CefPrintJobCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_job_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -291,17 +303,18 @@ impl CefPrintJobCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Indicate completion of the print job.
   //
   pub fn cont(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -328,7 +341,8 @@ impl CefWrap<*mut cef_print_job_callback_t> for Option<CefPrintJobCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_job_callback_t) -> Option<CefPrintJobCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefPrintJobCallback::from_c_object_addref(c_object))
@@ -385,13 +399,13 @@ pub struct _cef_print_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_print_handler_t = _cef_print_handler_t;
 
@@ -407,7 +421,8 @@ pub struct CefPrintHandler {
 impl Clone for CefPrintHandler {
   fn clone(&self) -> CefPrintHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintHandler {
@@ -420,7 +435,8 @@ impl Clone for CefPrintHandler {
 impl Drop for CefPrintHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -435,7 +451,8 @@ impl CefPrintHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_handler_t) -> CefPrintHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintHandler {
@@ -449,7 +466,8 @@ impl CefPrintHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -457,10 +475,10 @@ impl CefPrintHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -470,7 +488,8 @@ impl CefPrintHandler {
   //
   pub fn on_print_settings(&self, settings: interfaces::CefPrintSettings,
       get_defaults: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -489,7 +508,8 @@ impl CefPrintHandler {
   //
   pub fn on_print_dialog(&self, has_selection: libc::c_int,
       callback: interfaces::CefPrintDialogCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -508,7 +528,8 @@ impl CefPrintHandler {
   //
   pub fn on_print_job(&self, document_name: &[u16], pdf_file_path: &[u16],
       callback: interfaces::CefPrintJobCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -525,7 +546,8 @@ impl CefPrintHandler {
   // Reset client state related to printing.
   //
   pub fn on_print_reset(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -552,7 +574,8 @@ impl CefWrap<*mut cef_print_handler_t> for Option<CefPrintHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_handler_t) -> Option<CefPrintHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefPrintHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_print_settings.rs b/servo/ports/cef/interfaces/cef_print_settings.rs
index 1a79e25bcc57..2c22df782ad9 100644
--- a/servo/ports/cef/interfaces/cef_print_settings.rs
+++ b/servo/ports/cef/interfaces/cef_print_settings.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -206,13 +207,13 @@ pub struct _cef_print_settings_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_print_settings_t = _cef_print_settings_t;
 
@@ -227,7 +228,8 @@ pub struct CefPrintSettings {
 impl Clone for CefPrintSettings {
   fn clone(&self) -> CefPrintSettings{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintSettings {
@@ -240,7 +242,8 @@ impl Clone for CefPrintSettings {
 impl Drop for CefPrintSettings {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -255,7 +258,8 @@ impl CefPrintSettings {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_settings_t) -> CefPrintSettings {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintSettings {
@@ -269,7 +273,8 @@ impl CefPrintSettings {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_settings_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -277,10 +282,10 @@ impl CefPrintSettings {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -288,7 +293,8 @@ impl CefPrintSettings {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -303,7 +309,8 @@ impl CefPrintSettings {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -317,7 +324,8 @@ impl CefPrintSettings {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefPrintSettings {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -331,7 +339,8 @@ impl CefPrintSettings {
   // Set the page orientation.
   //
   pub fn set_orientation(&self, landscape: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -346,7 +355,8 @@ impl CefPrintSettings {
   // Returns true (1) if the orientation is landscape.
   //
   pub fn is_landscape(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -365,7 +375,8 @@ impl CefPrintSettings {
       physical_size_device_units: &types::cef_size_t,
       printable_area_device_units: &types::cef_rect_t,
       landscape_needs_flip: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -382,7 +393,8 @@ impl CefPrintSettings {
   // Set the device name.
   //
   pub fn set_device_name(&self, name: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -398,7 +410,8 @@ impl CefPrintSettings {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_device_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -412,7 +425,8 @@ impl CefPrintSettings {
   // Set the DPI (dots per inch).
   //
   pub fn set_dpi(&self, dpi: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -427,7 +441,8 @@ impl CefPrintSettings {
   // Get the DPI (dots per inch).
   //
   pub fn get_dpi(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -442,7 +457,8 @@ impl CefPrintSettings {
   //
   pub fn set_page_ranges(&self, ranges_count: libc::size_t,
       ranges: *const types::cef_page_range_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -458,7 +474,8 @@ impl CefPrintSettings {
   // Returns the number of page ranges that currently exist.
   //
   pub fn get_page_ranges_count(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -473,7 +490,8 @@ impl CefPrintSettings {
   //
   pub fn get_page_ranges(&self, ranges_count: *mut libc::size_t,
       ranges: *mut types::cef_page_range_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -489,7 +507,8 @@ impl CefPrintSettings {
   // Set whether only the selection will be printed.
   //
   pub fn set_selection_only(&self, selection_only: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -504,7 +523,8 @@ impl CefPrintSettings {
   // Returns true (1) if only the selection will be printed.
   //
   pub fn is_selection_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -518,7 +538,8 @@ impl CefPrintSettings {
   // Set whether pages will be collated.
   //
   pub fn set_collate(&self, collate: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -533,7 +554,8 @@ impl CefPrintSettings {
   // Returns true (1) if pages will be collated.
   //
   pub fn will_collate(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -547,7 +569,8 @@ impl CefPrintSettings {
   // Set the color model.
   //
   pub fn set_color_model(&self, model: types::cef_color_model_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -562,7 +585,8 @@ impl CefPrintSettings {
   // Get the color model.
   //
   pub fn get_color_model(&self) -> types::cef_color_model_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -576,7 +600,8 @@ impl CefPrintSettings {
   // Set the number of copies.
   //
   pub fn set_copies(&self, copies: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -591,7 +616,8 @@ impl CefPrintSettings {
   // Get the number of copies.
   //
   pub fn get_copies(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -605,7 +631,8 @@ impl CefPrintSettings {
   // Set the duplex mode.
   //
   pub fn set_duplex_mode(&self, mode: types::cef_duplex_mode_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -620,7 +647,8 @@ impl CefPrintSettings {
   // Get the duplex mode.
   //
   pub fn get_duplex_mode(&self) -> types::cef_duplex_mode_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -658,7 +686,8 @@ impl CefWrap<*mut cef_print_settings_t> for Option<CefPrintSettings> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_settings_t) -> Option<CefPrintSettings> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefPrintSettings::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_process_message.rs b/servo/ports/cef/interfaces/cef_process_message.rs
index ef6d896f2272..e09b4b1ee158 100644
--- a/servo/ports/cef/interfaces/cef_process_message.rs
+++ b/servo/ports/cef/interfaces/cef_process_message.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -91,13 +92,13 @@ pub struct _cef_process_message_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_process_message_t = _cef_process_message_t;
 
@@ -112,7 +113,8 @@ pub struct CefProcessMessage {
 impl Clone for CefProcessMessage {
   fn clone(&self) -> CefProcessMessage{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefProcessMessage {
@@ -125,7 +127,8 @@ impl Clone for CefProcessMessage {
 impl Drop for CefProcessMessage {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -140,7 +143,8 @@ impl CefProcessMessage {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_process_message_t) -> CefProcessMessage {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefProcessMessage {
@@ -154,7 +158,8 @@ impl CefProcessMessage {
 
   pub fn c_object_addrefed(&self) -> *mut cef_process_message_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -162,10 +167,10 @@ impl CefProcessMessage {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -173,7 +178,8 @@ impl CefProcessMessage {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -188,7 +194,8 @@ impl CefProcessMessage {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -202,7 +209,8 @@ impl CefProcessMessage {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefProcessMessage {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -217,7 +225,8 @@ impl CefProcessMessage {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -231,7 +240,8 @@ impl CefProcessMessage {
   // Returns the list of arguments.
   //
   pub fn get_argument_list(&self) -> interfaces::CefListValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -269,7 +279,8 @@ impl CefWrap<*mut cef_process_message_t> for Option<CefProcessMessage> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_process_message_t) -> Option<CefProcessMessage> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefProcessMessage::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_process_util.rs b/servo/ports/cef/interfaces/cef_process_util.rs
index c8622bc9cc9e..c396bf66e02e 100644
--- a/servo/ports/cef/interfaces/cef_process_util.rs
+++ b/servo/ports/cef/interfaces/cef_process_util.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,4 +43,5 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
diff --git a/servo/ports/cef/interfaces/cef_render_handler.rs b/servo/ports/cef/interfaces/cef_render_handler.rs
index 9f982c908658..68beac427ab1 100644
--- a/servo/ports/cef/interfaces/cef_render_handler.rs
+++ b/servo/ports/cef/interfaces/cef_render_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -103,18 +104,21 @@ pub struct _cef_render_handler_t {
 
   //
   // Called when the browser wants to move or resize the popup widget. |rect|
-  // contains the new location and size.
+  // contains the new location and size in view coordinates.
   //
   pub on_popup_size: Option<extern "C" fn(this: *mut cef_render_handler_t,
       browser: *mut interfaces::cef_browser_t,
       rect: *const types::cef_rect_t) -> ()>,
 
   //
-  // Called when an element should be painted. |type| indicates whether the
-  // element is the view or the popup widget. |buffer| contains the pixel data
-  // for the whole image. |dirtyRects| contains the set of rectangles that need
-  // to be repainted. On Windows |buffer| will be |width|*|height|*4 bytes in
-  // size and represents a BGRA image with an upper-left origin.
+  // Called when an element should be painted. Pixel values passed to this
+  // function are scaled relative to view coordinates based on the value of
+  // CefScreenInfo.device_scale_factor returned from GetScreenInfo. |type|
+  // indicates whether the element is the view or the popup widget. |buffer|
+  // contains the pixel data for the whole image. |dirtyRects| contains the set
+  // of rectangles in pixel coordinates that need to be repainted. |buffer| will
+  // be |width|*|height|*4 bytes in size and represents a BGRA image with an
+  // upper-left origin.
   //
   pub on_paint: Option<extern "C" fn(this: *mut cef_render_handler_t,
       browser: *mut interfaces::cef_browser_t,
@@ -123,16 +127,19 @@ pub struct _cef_render_handler_t {
       width: libc::c_int, height: libc::c_int) -> ()>,
 
   //
-  // Called when the browser window's cursor has changed.
+  // Called when the browser's cursor has changed. If |type| is CT_CUSTOM then
+  // |custom_cursor_info| will be populated with the custom cursor information.
   //
   pub on_cursor_change: Option<extern "C" fn(this: *mut cef_render_handler_t,
       browser: *mut interfaces::cef_browser_t,
-      cursor: types::cef_cursor_handle_t) -> ()>,
+      cursor: types::cef_cursor_handle_t, ty: types::cef_cursor_type_t,
+      custom_cursor_info: *const interfaces::cef_cursor_info_t) -> ()>,
 
   //
   // Called when the user starts dragging content in the web view. Contextual
-  // information about the dragged content is supplied by |drag_data|. OS APIs
-  // that run a system message loop may be used within the StartDragging call.
+  // information about the dragged content is supplied by |drag_data|. (|x|,
+  // |y|) is the drag start location in screen coordinates. OS APIs that run a
+  // system message loop may be used within the StartDragging call.
   //
   // Return false (0) to abort the drag operation. Don't call any of
   // cef_browser_host_t::DragSource*Ended* functions after returning false (0).
@@ -161,8 +168,8 @@ pub struct _cef_render_handler_t {
   // Called when the scroll offset has changed.
   //
   pub on_scroll_offset_changed: Option<extern "C" fn(
-      this: *mut cef_render_handler_t,
-      browser: *mut interfaces::cef_browser_t) -> ()>,
+      this: *mut cef_render_handler_t, browser: *mut interfaces::cef_browser_t,
+      x: libc::c_double, y: libc::c_double) -> ()>,
 
   //
   // Called to retrieve the backing size of the view rectangle which is relative
@@ -184,13 +191,13 @@ pub struct _cef_render_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_render_handler_t = _cef_render_handler_t;
 
@@ -206,7 +213,8 @@ pub struct CefRenderHandler {
 impl Clone for CefRenderHandler {
   fn clone(&self) -> CefRenderHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRenderHandler {
@@ -219,7 +227,8 @@ impl Clone for CefRenderHandler {
 impl Drop for CefRenderHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -234,7 +243,8 @@ impl CefRenderHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_render_handler_t) -> CefRenderHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRenderHandler {
@@ -248,7 +258,8 @@ impl CefRenderHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_render_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -256,10 +267,10 @@ impl CefRenderHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -268,7 +279,8 @@ impl CefRenderHandler {
   //
   pub fn get_root_screen_rect(&self, browser: interfaces::CefBrowser,
       rect: &mut types::cef_rect_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -286,7 +298,8 @@ impl CefRenderHandler {
   //
   pub fn get_view_rect(&self, browser: interfaces::CefBrowser,
       rect: &mut types::cef_rect_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -305,7 +318,8 @@ impl CefRenderHandler {
   pub fn get_screen_point(&self, browser: interfaces::CefBrowser,
       viewX: libc::c_int, viewY: libc::c_int, screenX: &mut libc::c_int,
       screenY: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -331,7 +345,8 @@ impl CefRenderHandler {
   //
   pub fn get_screen_info(&self, browser: interfaces::CefBrowser,
       screen_info: &mut interfaces::CefScreenInfo) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -349,7 +364,8 @@ impl CefRenderHandler {
   //
   pub fn on_popup_show(&self, browser: interfaces::CefBrowser,
       show: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -363,11 +379,12 @@ impl CefRenderHandler {
 
   //
   // Called when the browser wants to move or resize the popup widget. |rect|
-  // contains the new location and size.
+  // contains the new location and size in view coordinates.
   //
   pub fn on_popup_size(&self, browser: interfaces::CefBrowser,
       rect: &types::cef_rect_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -380,17 +397,21 @@ impl CefRenderHandler {
   }
 
   //
-  // Called when an element should be painted. |type| indicates whether the
-  // element is the view or the popup widget. |buffer| contains the pixel data
-  // for the whole image. |dirtyRects| contains the set of rectangles that need
-  // to be repainted. On Windows |buffer| will be |width|*|height|*4 bytes in
-  // size and represents a BGRA image with an upper-left origin.
+  // Called when an element should be painted. Pixel values passed to this
+  // function are scaled relative to view coordinates based on the value of
+  // CefScreenInfo.device_scale_factor returned from GetScreenInfo. |type|
+  // indicates whether the element is the view or the popup widget. |buffer|
+  // contains the pixel data for the whole image. |dirtyRects| contains the set
+  // of rectangles in pixel coordinates that need to be repainted. |buffer| will
+  // be |width|*|height|*4 bytes in size and represents a BGRA image with an
+  // upper-left origin.
   //
   pub fn on_paint(&self, browser: interfaces::CefBrowser,
       ty: types::cef_paint_element_type_t, dirtyRects_count: libc::size_t,
       dirtyRects: *const types::cef_rect_t, buffer: &(), width: libc::c_int,
       height: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -408,11 +429,14 @@ impl CefRenderHandler {
   }
 
   //
-  // Called when the browser window's cursor has changed.
+  // Called when the browser's cursor has changed. If |type| is CT_CUSTOM then
+  // |custom_cursor_info| will be populated with the custom cursor information.
   //
   pub fn on_cursor_change(&self, browser: interfaces::CefBrowser,
-      cursor: types::cef_cursor_handle_t) -> () {
-    if self.c_object.is_null() {
+      cursor: types::cef_cursor_handle_t, ty: types::cef_cursor_type_t,
+      custom_cursor_info: &interfaces::CefCursorInfo) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -420,14 +444,17 @@ impl CefRenderHandler {
         ((*self.c_object).on_cursor_change.unwrap())(
           self.c_object,
           CefWrap::to_c(browser),
-          CefWrap::to_c(cursor)))
+          CefWrap::to_c(cursor),
+          CefWrap::to_c(ty),
+          CefWrap::to_c(custom_cursor_info)))
     }
   }
 
   //
   // Called when the user starts dragging content in the web view. Contextual
-  // information about the dragged content is supplied by |drag_data|. OS APIs
-  // that run a system message loop may be used within the StartDragging call.
+  // information about the dragged content is supplied by |drag_data|. (|x|,
+  // |y|) is the drag start location in screen coordinates. OS APIs that run a
+  // system message loop may be used within the StartDragging call.
   //
   // Return false (0) to abort the drag operation. Don't call any of
   // cef_browser_host_t::DragSource*Ended* functions after returning false (0).
@@ -441,7 +468,8 @@ impl CefRenderHandler {
       drag_data: interfaces::CefDragData,
       allowed_ops: types::cef_drag_operations_mask_t, x: libc::c_int,
       y: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -463,7 +491,8 @@ impl CefRenderHandler {
   //
   pub fn update_drag_cursor(&self, browser: interfaces::CefBrowser,
       operation: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -478,16 +507,19 @@ impl CefRenderHandler {
   //
   // Called when the scroll offset has changed.
   //
-  pub fn on_scroll_offset_changed(&self, browser: interfaces::CefBrowser) -> (
-      ) {
-    if self.c_object.is_null() {
+  pub fn on_scroll_offset_changed(&self, browser: interfaces::CefBrowser,
+      x: libc::c_double, y: libc::c_double) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
       CefWrap::to_rust(
         ((*self.c_object).on_scroll_offset_changed.unwrap())(
           self.c_object,
-          CefWrap::to_c(browser)))
+          CefWrap::to_c(browser),
+          CefWrap::to_c(x),
+          CefWrap::to_c(y)))
     }
   }
 
@@ -499,7 +531,8 @@ impl CefRenderHandler {
   //
   pub fn get_backing_rect(&self, browser: interfaces::CefBrowser,
       rect: &mut types::cef_rect_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -516,7 +549,8 @@ impl CefRenderHandler {
   // flip). This is called only during accelerated compositing.
   //
   pub fn on_present(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -544,7 +578,8 @@ impl CefWrap<*mut cef_render_handler_t> for Option<CefRenderHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_render_handler_t) -> Option<CefRenderHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRenderHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_render_process_handler.rs b/servo/ports/cef/interfaces/cef_render_process_handler.rs
index da4a513371a4..c334c9520e87 100644
--- a/servo/ports/cef/interfaces/cef_render_process_handler.rs
+++ b/servo/ports/cef/interfaces/cef_render_process_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -173,13 +174,13 @@ pub struct _cef_render_process_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_render_process_handler_t = _cef_render_process_handler_t;
 
@@ -196,7 +197,8 @@ pub struct CefRenderProcessHandler {
 impl Clone for CefRenderProcessHandler {
   fn clone(&self) -> CefRenderProcessHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRenderProcessHandler {
@@ -209,7 +211,8 @@ impl Clone for CefRenderProcessHandler {
 impl Drop for CefRenderProcessHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -224,7 +227,8 @@ impl CefRenderProcessHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_render_process_handler_t) -> CefRenderProcessHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRenderProcessHandler {
@@ -238,7 +242,8 @@ impl CefRenderProcessHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_render_process_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -246,10 +251,10 @@ impl CefRenderProcessHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -260,7 +265,8 @@ impl CefRenderProcessHandler {
   //
   pub fn on_render_thread_created(&self,
       extra_info: interfaces::CefListValue) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -275,7 +281,8 @@ impl CefRenderProcessHandler {
   // Called after WebKit has been initialized.
   //
   pub fn on_web_kit_initialized(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,7 +298,8 @@ impl CefRenderProcessHandler {
   // destroyed.
   //
   pub fn on_browser_created(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,7 +314,8 @@ impl CefRenderProcessHandler {
   // Called before a browser is destroyed.
   //
   pub fn on_browser_destroyed(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -321,7 +330,8 @@ impl CefRenderProcessHandler {
   // Return the handler for browser load status events.
   //
   pub fn get_load_handler(&self) -> interfaces::CefLoadHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -340,7 +350,8 @@ impl CefRenderProcessHandler {
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       navigation_type: types::cef_navigation_type_t,
       is_redirect: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -365,7 +376,8 @@ impl CefRenderProcessHandler {
   //
   pub fn on_context_created(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, context: interfaces::CefV8Context) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -384,7 +396,8 @@ impl CefRenderProcessHandler {
   //
   pub fn on_context_released(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, context: interfaces::CefV8Context) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -406,7 +419,8 @@ impl CefRenderProcessHandler {
       frame: interfaces::CefFrame, context: interfaces::CefV8Context,
       exception: interfaces::CefV8Exception,
       stackTrace: interfaces::CefV8StackTrace) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -431,7 +445,8 @@ impl CefRenderProcessHandler {
   //
   pub fn on_focused_node_changed(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, node: interfaces::CefDOMNode) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -452,7 +467,8 @@ impl CefRenderProcessHandler {
   pub fn on_process_message_received(&self, browser: interfaces::CefBrowser,
       source_process: interfaces::CefProcessId,
       message: interfaces::CefProcessMessage) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -482,7 +498,8 @@ impl CefWrap<*mut cef_render_process_handler_t> for Option<CefRenderProcessHandl
     }
   }
   unsafe fn to_rust(c_object: *mut cef_render_process_handler_t) -> Option<CefRenderProcessHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRenderProcessHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_request.rs b/servo/ports/cef/interfaces/cef_request.rs
index 097065efa8d0..171d3c303140 100644
--- a/servo/ports/cef/interfaces/cef_request.rs
+++ b/servo/ports/cef/interfaces/cef_request.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -164,16 +165,23 @@ pub struct _cef_request_t {
   pub get_transition_type: Option<extern "C" fn(
       this: *mut cef_request_t) -> types::cef_transition_type_t>,
 
+  //
+  // Returns the globally unique identifier for this request or 0 if not
+  // specified. Can be used by cef_request_tHandler implementations in the
+  // browser process to track a single request across multiple callbacks.
+  //
+  pub get_identifier: Option<extern "C" fn(this: *mut cef_request_t) -> u64>,
+
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_request_t = _cef_request_t;
 
@@ -189,7 +197,8 @@ pub struct CefRequest {
 impl Clone for CefRequest {
   fn clone(&self) -> CefRequest{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequest {
@@ -202,7 +211,8 @@ impl Clone for CefRequest {
 impl Drop for CefRequest {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -217,7 +227,8 @@ impl CefRequest {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_t) -> CefRequest {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequest {
@@ -231,7 +242,8 @@ impl CefRequest {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -239,17 +251,18 @@ impl CefRequest {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -264,7 +277,8 @@ impl CefRequest {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -278,7 +292,8 @@ impl CefRequest {
   // Set the fully qualified URL.
   //
   pub fn set_url(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -295,7 +310,8 @@ impl CefRequest {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_method(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -309,7 +325,8 @@ impl CefRequest {
   // Set the request function type.
   //
   pub fn set_method(&self, method: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -324,7 +341,8 @@ impl CefRequest {
   // Get the post data.
   //
   pub fn get_post_data(&self) -> interfaces::CefPostData {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -338,7 +356,8 @@ impl CefRequest {
   // Set the post data.
   //
   pub fn set_post_data(&self, postData: interfaces::CefPostData) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -353,7 +372,8 @@ impl CefRequest {
   // Get the header values.
   //
   pub fn get_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -368,7 +388,8 @@ impl CefRequest {
   // Set the header values.
   //
   pub fn set_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -385,7 +406,8 @@ impl CefRequest {
   pub fn set(&self, url: &[u16], method: &[u16],
       postData: interfaces::CefPostData, headerMap: HashMap<String,
       Vec<String>>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -404,7 +426,8 @@ impl CefRequest {
   // cef_urlrequest_flags_t for supported values.
   //
   pub fn get_flags(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -419,7 +442,8 @@ impl CefRequest {
   // cef_urlrequest_flags_t for supported values.
   //
   pub fn set_flags(&self, flags: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -436,7 +460,8 @@ impl CefRequest {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_first_party_for_cookies(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -451,7 +476,8 @@ impl CefRequest {
   // cef_urlrequest_t.
   //
   pub fn set_first_party_for_cookies(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -467,7 +493,8 @@ impl CefRequest {
   // process.
   //
   pub fn get_resource_type(&self) -> types::cef_resource_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -483,7 +510,8 @@ impl CefRequest {
   // frame navigation.
   //
   pub fn get_transition_type(&self) -> types::cef_transition_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -493,6 +521,23 @@ impl CefRequest {
     }
   }
 
+  //
+  // Returns the globally unique identifier for this request or 0 if not
+  // specified. Can be used by cef_request_tHandler implementations in the
+  // browser process to track a single request across multiple callbacks.
+  //
+  pub fn get_identifier(&self) -> u64 {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_identifier.unwrap())(
+          self.c_object))
+    }
+  }
+
   //
   // Create a new cef_request_t object.
   //
@@ -521,7 +566,8 @@ impl CefWrap<*mut cef_request_t> for Option<CefRequest> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_t) -> Option<CefRequest> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRequest::from_c_object_addref(c_object))
@@ -581,13 +627,13 @@ pub struct _cef_post_data_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_post_data_t = _cef_post_data_t;
 
@@ -603,7 +649,8 @@ pub struct CefPostData {
 impl Clone for CefPostData {
   fn clone(&self) -> CefPostData{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPostData {
@@ -616,7 +663,8 @@ impl Clone for CefPostData {
 impl Drop for CefPostData {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -631,7 +679,8 @@ impl CefPostData {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_post_data_t) -> CefPostData {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPostData {
@@ -645,7 +694,8 @@ impl CefPostData {
 
   pub fn c_object_addrefed(&self) -> *mut cef_post_data_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -653,17 +703,18 @@ impl CefPostData {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -677,7 +728,8 @@ impl CefPostData {
   // Returns the number of existing post data elements.
   //
   pub fn get_element_count(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -692,7 +744,8 @@ impl CefPostData {
   //
   pub fn get_elements(&self, elements_count: *mut libc::size_t,
       elements: *mut interfaces::CefPostDataElement) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -710,7 +763,8 @@ impl CefPostData {
   //
   pub fn remove_element(&self,
       element: interfaces::CefPostDataElement) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -726,7 +780,8 @@ impl CefPostData {
   //
   pub fn add_element(&self,
       element: interfaces::CefPostDataElement) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -741,7 +796,8 @@ impl CefPostData {
   // Remove all existing post data elements.
   //
   pub fn remove_elements(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -779,7 +835,8 @@ impl CefWrap<*mut cef_post_data_t> for Option<CefPostData> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_post_data_t) -> Option<CefPostData> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefPostData::from_c_object_addref(c_object))
@@ -853,13 +910,13 @@ pub struct _cef_post_data_element_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_post_data_element_t = _cef_post_data_element_t;
 
@@ -875,7 +932,8 @@ pub struct CefPostDataElement {
 impl Clone for CefPostDataElement {
   fn clone(&self) -> CefPostDataElement{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPostDataElement {
@@ -888,7 +946,8 @@ impl Clone for CefPostDataElement {
 impl Drop for CefPostDataElement {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -903,7 +962,8 @@ impl CefPostDataElement {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_post_data_element_t) -> CefPostDataElement {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPostDataElement {
@@ -917,7 +977,8 @@ impl CefPostDataElement {
 
   pub fn c_object_addrefed(&self) -> *mut cef_post_data_element_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -925,17 +986,18 @@ impl CefPostDataElement {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -949,7 +1011,8 @@ impl CefPostDataElement {
   // Remove all contents from the post data element.
   //
   pub fn set_to_empty(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -963,7 +1026,8 @@ impl CefPostDataElement {
   // The post data element will represent a file.
   //
   pub fn set_to_file(&self, fileName: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -979,7 +1043,8 @@ impl CefPostDataElement {
   // copied.
   //
   pub fn set_to_bytes(&self, size: libc::size_t, bytes: &()) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -995,7 +1060,8 @@ impl CefPostDataElement {
   // Return the type of this post data element.
   //
   pub fn get_type(&self) -> types::cef_postdataelement_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1010,7 +1076,8 @@ impl CefPostDataElement {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_file(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1024,7 +1091,8 @@ impl CefPostDataElement {
   // Return the number of bytes.
   //
   pub fn get_bytes_count(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1039,7 +1107,8 @@ impl CefPostDataElement {
   // actually read.
   //
   pub fn get_bytes(&self, size: libc::size_t, bytes: &mut ()) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1079,7 +1148,8 @@ impl CefWrap<*mut cef_post_data_element_t> for Option<CefPostDataElement> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_post_data_element_t) -> Option<CefPostDataElement> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefPostDataElement::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_request_context.rs b/servo/ports/cef/interfaces/cef_request_context.rs
index e5de378a71e7..7f4f4fc975b2 100644
--- a/servo/ports/cef/interfaces/cef_request_context.rs
+++ b/servo/ports/cef/interfaces/cef_request_context.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,22 +43,24 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
-// A request context provides request handling for a set of related browser
-// objects. A request context is specified when creating a new browser object
-// via the cef_browser_host_t static factory functions. Browser objects with
-// different request contexts will never be hosted in the same render process.
-// Browser objects with the same request context may or may not be hosted in the
-// same render process depending on the process model. Browser objects created
-// indirectly via the JavaScript window.open function or targeted links will
-// share the same render process and the same request context as the source
-// browser. When running in single-process mode there is only a single render
-// process (the main process) and so all browsers created in single-process mode
-// will share the same request context. This will be the first request context
-// passed into a cef_browser_host_t static factory function and all other
-// request context objects will be ignored.
+// A request context provides request handling for a set of related browser or
+// URL request objects. A request context can be specified when creating a new
+// browser via the cef_browser_host_t static factory functions or when creating
+// a new URL request via the cef_urlrequest_t static factory functions. Browser
+// objects with different request contexts will never be hosted in the same
+// render process. Browser objects with the same request context may or may not
+// be hosted in the same render process depending on the process model. Browser
+// objects created indirectly via the JavaScript window.open function or
+// targeted links will share the same render process and the same request
+// context as the source browser. When running in single-process mode there is
+// only a single render process (the main process) and so all browsers created
+// in single-process mode will share the same request context. This will be the
+// first request context passed into a cef_browser_host_t static factory
+// function and all other request context objects will be ignored.
 //
 #[repr(C)]
 pub struct _cef_request_context_t {
@@ -75,7 +77,16 @@ pub struct _cef_request_context_t {
       other: *mut interfaces::cef_request_context_t) -> libc::c_int>,
 
   //
-  // Returns true (1) if this object is the global context.
+  // Returns true (1) if this object is sharing the same storage as |that|
+  // object.
+  //
+  pub is_sharing_with: Option<extern "C" fn(this: *mut cef_request_context_t,
+      other: *mut interfaces::cef_request_context_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if this object is the global context. The global context
+  // is used by default when creating a browser or URL request with a NULL
+  // context argument.
   //
   pub is_global: Option<extern "C" fn(
       this: *mut cef_request_context_t) -> libc::c_int>,
@@ -86,34 +97,80 @@ pub struct _cef_request_context_t {
   pub get_handler: Option<extern "C" fn(
       this: *mut cef_request_context_t) -> *mut interfaces::cef_request_context_handler_t>,
 
+  //
+  // Returns the cache path for this object. If NULL an "incognito mode" in-
+  // memory cache is being used.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_cache_path: Option<extern "C" fn(
+      this: *mut cef_request_context_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the default cookie manager for this object. This will be the global
+  // cookie manager if this object is the global request context. Otherwise,
+  // this will be the default cookie manager used when this request context does
+  // not receive a value via cef_request_tContextHandler::get_cookie_manager().
+  // If |callback| is non-NULL it will be executed asnychronously on the IO
+  // thread after the manager's storage has been initialized.
+  //
+  pub get_default_cookie_manager: Option<extern "C" fn(
+      this: *mut cef_request_context_t,
+      callback: *mut interfaces::cef_completion_callback_t) -> *mut interfaces::cef_cookie_manager_t>,
+
+  //
+  // Register a scheme handler factory for the specified |scheme_name| and
+  // optional |domain_name|. An NULL |domain_name| value for a standard scheme
+  // will cause the factory to match all domain names. The |domain_name| value
+  // will be ignored for non-standard schemes. If |scheme_name| is a built-in
+  // scheme and no handler is returned by |factory| then the built-in scheme
+  // handler factory will be called. If |scheme_name| is a custom scheme then
+  // you must also implement the cef_app_t::on_register_custom_schemes()
+  // function in all processes. This function may be called multiple times to
+  // change or remove the factory that matches the specified |scheme_name| and
+  // optional |domain_name|. Returns false (0) if an error occurs. This function
+  // may be called on any thread in the browser process.
+  //
+  pub register_scheme_handler_factory: Option<extern "C" fn(
+      this: *mut cef_request_context_t, scheme_name: *const types::cef_string_t,
+      domain_name: *const types::cef_string_t,
+      factory: *mut interfaces::cef_scheme_handler_factory_t) -> libc::c_int>,
+
+  //
+  // Clear all registered scheme handler factories. Returns false (0) on error.
+  // This function may be called on any thread in the browser process.
+  //
+  pub clear_scheme_handler_factories: Option<extern "C" fn(
+      this: *mut cef_request_context_t) -> libc::c_int>,
+
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_request_context_t = _cef_request_context_t;
 
 
 //
-// A request context provides request handling for a set of related browser
-// objects. A request context is specified when creating a new browser object
-// via the cef_browser_host_t static factory functions. Browser objects with
-// different request contexts will never be hosted in the same render process.
-// Browser objects with the same request context may or may not be hosted in the
-// same render process depending on the process model. Browser objects created
-// indirectly via the JavaScript window.open function or targeted links will
-// share the same render process and the same request context as the source
-// browser. When running in single-process mode there is only a single render
-// process (the main process) and so all browsers created in single-process mode
-// will share the same request context. This will be the first request context
-// passed into a cef_browser_host_t static factory function and all other
-// request context objects will be ignored.
+// A request context provides request handling for a set of related browser or
+// URL request objects. A request context can be specified when creating a new
+// browser via the cef_browser_host_t static factory functions or when creating
+// a new URL request via the cef_urlrequest_t static factory functions. Browser
+// objects with different request contexts will never be hosted in the same
+// render process. Browser objects with the same request context may or may not
+// be hosted in the same render process depending on the process model. Browser
+// objects created indirectly via the JavaScript window.open function or
+// targeted links will share the same render process and the same request
+// context as the source browser. When running in single-process mode there is
+// only a single render process (the main process) and so all browsers created
+// in single-process mode will share the same request context. This will be the
+// first request context passed into a cef_browser_host_t static factory
+// function and all other request context objects will be ignored.
 //
 pub struct CefRequestContext {
   c_object: *mut cef_request_context_t,
@@ -122,7 +179,8 @@ pub struct CefRequestContext {
 impl Clone for CefRequestContext {
   fn clone(&self) -> CefRequestContext{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestContext {
@@ -135,7 +193,8 @@ impl Clone for CefRequestContext {
 impl Drop for CefRequestContext {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -150,7 +209,8 @@ impl CefRequestContext {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_context_t) -> CefRequestContext {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestContext {
@@ -164,7 +224,8 @@ impl CefRequestContext {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_context_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -172,10 +233,10 @@ impl CefRequestContext {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -183,7 +244,8 @@ impl CefRequestContext {
   // object.
   //
   pub fn is_same(&self, other: interfaces::CefRequestContext) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -195,10 +257,31 @@ impl CefRequestContext {
   }
 
   //
-  // Returns true (1) if this object is the global context.
+  // Returns true (1) if this object is sharing the same storage as |that|
+  // object.
+  //
+  pub fn is_sharing_with(&self,
+      other: interfaces::CefRequestContext) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_sharing_with.unwrap())(
+          self.c_object,
+          CefWrap::to_c(other)))
+    }
+  }
+
+  //
+  // Returns true (1) if this object is the global context. The global context
+  // is used by default when creating a browser or URL request with a NULL
+  // context argument.
   //
   pub fn is_global(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -212,7 +295,8 @@ impl CefRequestContext {
   // Returns the handler for this context if any.
   //
   pub fn get_handler(&self) -> interfaces::CefRequestContextHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -222,6 +306,91 @@ impl CefRequestContext {
     }
   }
 
+  //
+  // Returns the cache path for this object. If NULL an "incognito mode" in-
+  // memory cache is being used.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_cache_path(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_cache_path.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the default cookie manager for this object. This will be the global
+  // cookie manager if this object is the global request context. Otherwise,
+  // this will be the default cookie manager used when this request context does
+  // not receive a value via cef_request_tContextHandler::get_cookie_manager().
+  // If |callback| is non-NULL it will be executed asnychronously on the IO
+  // thread after the manager's storage has been initialized.
+  //
+  pub fn get_default_cookie_manager(&self,
+      callback: interfaces::CefCompletionCallback) -> interfaces::CefCookieManager {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_default_cookie_manager.unwrap())(
+          self.c_object,
+          CefWrap::to_c(callback)))
+    }
+  }
+
+  //
+  // Register a scheme handler factory for the specified |scheme_name| and
+  // optional |domain_name|. An NULL |domain_name| value for a standard scheme
+  // will cause the factory to match all domain names. The |domain_name| value
+  // will be ignored for non-standard schemes. If |scheme_name| is a built-in
+  // scheme and no handler is returned by |factory| then the built-in scheme
+  // handler factory will be called. If |scheme_name| is a custom scheme then
+  // you must also implement the cef_app_t::on_register_custom_schemes()
+  // function in all processes. This function may be called multiple times to
+  // change or remove the factory that matches the specified |scheme_name| and
+  // optional |domain_name|. Returns false (0) if an error occurs. This function
+  // may be called on any thread in the browser process.
+  //
+  pub fn register_scheme_handler_factory(&self, scheme_name: &[u16],
+      domain_name: &[u16],
+      factory: interfaces::CefSchemeHandlerFactory) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).register_scheme_handler_factory.unwrap())(
+          self.c_object,
+          CefWrap::to_c(scheme_name),
+          CefWrap::to_c(domain_name),
+          CefWrap::to_c(factory)))
+    }
+  }
+
+  //
+  // Clear all registered scheme handler factories. Returns false (0) on error.
+  // This function may be called on any thread in the browser process.
+  //
+  pub fn clear_scheme_handler_factories(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).clear_scheme_handler_factories.unwrap())(
+          self.c_object))
+    }
+  }
+
   //
   // Returns the global context object.
   //
@@ -234,13 +403,29 @@ impl CefRequestContext {
   }
 
   //
-  // Creates a new context object with the specified handler.
+  // Creates a new context object with the specified |settings| and optional
+  // |handler|.
   //
-  pub fn create_context(
+  pub fn create_context(settings: &interfaces::CefRequestContextSettings,
       handler: interfaces::CefRequestContextHandler) -> interfaces::CefRequestContext {
     unsafe {
       CefWrap::to_rust(
         ::request_context::cef_request_context_create_context(
+          CefWrap::to_c(settings),
+          CefWrap::to_c(handler)))
+    }
+  }
+
+  //
+  // Creates a new context object that shares storage with |other| and uses an
+  // optional |handler|.
+  //
+  pub fn create_context_shared(other: interfaces::CefRequestContext,
+      handler: interfaces::CefRequestContextHandler) -> interfaces::CefRequestContext {
+    unsafe {
+      CefWrap::to_rust(
+        ::request_context::cef_request_context_create_context_shared(
+          CefWrap::to_c(other),
           CefWrap::to_c(handler)))
     }
   }
@@ -262,7 +447,8 @@ impl CefWrap<*mut cef_request_context_t> for Option<CefRequestContext> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_context_t) -> Option<CefRequestContext> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRequestContext::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_request_context_handler.rs b/servo/ports/cef/interfaces/cef_request_context_handler.rs
index a331d984709a..91e41a1b91e1 100644
--- a/servo/ports/cef/interfaces/cef_request_context_handler.rs
+++ b/servo/ports/cef/interfaces/cef_request_context_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,10 +43,13 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
-// Implement this structure to provide handler implementations.
+// Implement this structure to provide handler implementations. The handler
+// instance will not be released until all objects related to the context have
+// been destroyed.
 //
 #[repr(C)]
 pub struct _cef_request_context_handler_t {
@@ -56,8 +59,9 @@ pub struct _cef_request_context_handler_t {
   pub base: types::cef_base_t,
 
   //
-  // Called on the IO thread to retrieve the cookie manager. The global cookie
-  // manager will be used if this function returns NULL.
+  // Called on the IO thread to retrieve the cookie manager. If this function
+  // returns NULL the default cookie manager retrievable via
+  // cef_request_tContext::get_default_cookie_manager() will be used.
   //
   pub get_cookie_manager: Option<extern "C" fn(
       this: *mut cef_request_context_handler_t) -> *mut interfaces::cef_cookie_manager_t>,
@@ -65,19 +69,21 @@ pub struct _cef_request_context_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_request_context_handler_t = _cef_request_context_handler_t;
 
 
 //
-// Implement this structure to provide handler implementations.
+// Implement this structure to provide handler implementations. The handler
+// instance will not be released until all objects related to the context have
+// been destroyed.
 //
 pub struct CefRequestContextHandler {
   c_object: *mut cef_request_context_handler_t,
@@ -86,7 +92,8 @@ pub struct CefRequestContextHandler {
 impl Clone for CefRequestContextHandler {
   fn clone(&self) -> CefRequestContextHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestContextHandler {
@@ -99,7 +106,8 @@ impl Clone for CefRequestContextHandler {
 impl Drop for CefRequestContextHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -114,7 +122,8 @@ impl CefRequestContextHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_context_handler_t) -> CefRequestContextHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestContextHandler {
@@ -128,7 +137,8 @@ impl CefRequestContextHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_context_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -136,18 +146,20 @@ impl CefRequestContextHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Called on the IO thread to retrieve the cookie manager. The global cookie
-  // manager will be used if this function returns NULL.
+  // Called on the IO thread to retrieve the cookie manager. If this function
+  // returns NULL the default cookie manager retrievable via
+  // cef_request_tContext::get_default_cookie_manager() will be used.
   //
   pub fn get_cookie_manager(&self) -> interfaces::CefCookieManager {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -174,7 +186,8 @@ impl CefWrap<*mut cef_request_context_handler_t> for Option<CefRequestContextHan
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_context_handler_t) -> Option<CefRequestContextHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRequestContextHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_request_handler.rs b/servo/ports/cef/interfaces/cef_request_handler.rs
index b0aed69c0a71..483d26adb9b6 100644
--- a/servo/ports/cef/interfaces/cef_request_handler.rs
+++ b/servo/ports/cef/interfaces/cef_request_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,97 +43,102 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
-// Callback structure used for asynchronous continuation of quota requests.
+// Callback structure used for asynchronous continuation of url requests.
 //
 #[repr(C)]
-pub struct _cef_quota_callback_t {
+pub struct _cef_request_callback_t {
   //
   // Base structure.
   //
   pub base: types::cef_base_t,
 
   //
-  // Continue the quota request. If |allow| is true (1) the request will be
-  // allowed. Otherwise, the request will be denied.
+  // Continue the url request. If |allow| is true (1) the request will be
+  // continued. Otherwise, the request will be canceled.
   //
-  pub cont: Option<extern "C" fn(this: *mut cef_quota_callback_t,
+  pub cont: Option<extern "C" fn(this: *mut cef_request_callback_t,
       allow: libc::c_int) -> ()>,
 
   //
-  // Cancel the quota request.
+  // Cancel the url request.
   //
-  pub cancel: Option<extern "C" fn(this: *mut cef_quota_callback_t) -> ()>,
+  pub cancel: Option<extern "C" fn(this: *mut cef_request_callback_t) -> ()>,
 
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
-
-pub type cef_quota_callback_t = _cef_quota_callback_t;
-
-
-//
-// Callback structure used for asynchronous continuation of quota requests.
-//
-pub struct CefQuotaCallback {
-  c_object: *mut cef_quota_callback_t,
 }
 
-impl Clone for CefQuotaCallback {
-  fn clone(&self) -> CefQuotaCallback{
+pub type cef_request_callback_t = _cef_request_callback_t;
+
+
+//
+// Callback structure used for asynchronous continuation of url requests.
+//
+pub struct CefRequestCallback {
+  c_object: *mut cef_request_callback_t,
+}
+
+impl Clone for CefRequestCallback {
+  fn clone(&self) -> CefRequestCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
-      CefQuotaCallback {
+      CefRequestCallback {
         c_object: self.c_object,
       }
     }
   }
 }
 
-impl Drop for CefQuotaCallback {
+impl Drop for CefRequestCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
   }
 }
 
-impl CefQuotaCallback {
-  pub unsafe fn from_c_object(c_object: *mut cef_quota_callback_t) -> CefQuotaCallback {
-    CefQuotaCallback {
+impl CefRequestCallback {
+  pub unsafe fn from_c_object(c_object: *mut cef_request_callback_t) -> CefRequestCallback {
+    CefRequestCallback {
       c_object: c_object,
     }
   }
 
-  pub unsafe fn from_c_object_addref(c_object: *mut cef_quota_callback_t) -> CefQuotaCallback {
-    if !c_object.is_null() {
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_request_callback_t) -> CefRequestCallback {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
-    CefQuotaCallback {
+    CefRequestCallback {
       c_object: c_object,
     }
   }
 
-  pub fn c_object(&self) -> *mut cef_quota_callback_t {
+  pub fn c_object(&self) -> *mut cef_request_callback_t {
     self.c_object
   }
 
-  pub fn c_object_addrefed(&self) -> *mut cef_quota_callback_t {
+  pub fn c_object_addrefed(&self) -> *mut cef_request_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -141,18 +146,19 @@ impl CefQuotaCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Continue the quota request. If |allow| is true (1) the request will be
-  // allowed. Otherwise, the request will be denied.
+  // Continue the url request. If |allow| is true (1) the request will be
+  // continued. Otherwise, the request will be canceled.
   //
   pub fn cont(&self, allow: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -164,10 +170,11 @@ impl CefQuotaCallback {
   }
 
   //
-  // Cancel the quota request.
+  // Cancel the url request.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -178,168 +185,27 @@ impl CefQuotaCallback {
   }
 } 
 
-impl CefWrap<*mut cef_quota_callback_t> for CefQuotaCallback {
-  fn to_c(rust_object: CefQuotaCallback) -> *mut cef_quota_callback_t {
+impl CefWrap<*mut cef_request_callback_t> for CefRequestCallback {
+  fn to_c(rust_object: CefRequestCallback) -> *mut cef_request_callback_t {
     rust_object.c_object_addrefed()
   }
-  unsafe fn to_rust(c_object: *mut cef_quota_callback_t) -> CefQuotaCallback {
-    CefQuotaCallback::from_c_object_addref(c_object)
+  unsafe fn to_rust(c_object: *mut cef_request_callback_t) -> CefRequestCallback {
+    CefRequestCallback::from_c_object_addref(c_object)
   }
 }
-impl CefWrap<*mut cef_quota_callback_t> for Option<CefQuotaCallback> {
-  fn to_c(rust_object: Option<CefQuotaCallback>) -> *mut cef_quota_callback_t {
+impl CefWrap<*mut cef_request_callback_t> for Option<CefRequestCallback> {
+  fn to_c(rust_object: Option<CefRequestCallback>) -> *mut cef_request_callback_t {
     match rust_object {
       None => ptr::null_mut(),
       Some(rust_object) => rust_object.c_object_addrefed(),
     }
   }
-  unsafe fn to_rust(c_object: *mut cef_quota_callback_t) -> Option<CefQuotaCallback> {
-    if c_object.is_null() {
+  unsafe fn to_rust(c_object: *mut cef_request_callback_t) -> Option<CefRequestCallback> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
-      Some(CefQuotaCallback::from_c_object_addref(c_object))
-    }
-  }
-}
-
-
-//
-// Callback structure used for asynchronous continuation of url requests when
-// invalid SSL certificates are encountered.
-//
-#[repr(C)]
-pub struct _cef_allow_certificate_error_callback_t {
-  //
-  // Base structure.
-  //
-  pub base: types::cef_base_t,
-
-  //
-  // Continue the url request. If |allow| is true (1) the request will be
-  // continued. Otherwise, the request will be canceled.
-  //
-  pub cont: Option<extern "C" fn(
-      this: *mut cef_allow_certificate_error_callback_t,
-      allow: libc::c_int) -> ()>,
-
-  //
-  // The reference count. This will only be present for Rust instances!
-  //
-  pub ref_count: usize,
-
-  //
-  // Extra data. This will only be present for Rust instances!
-  //
-  pub extra: u8,
-} 
-
-pub type cef_allow_certificate_error_callback_t = _cef_allow_certificate_error_callback_t;
-
-
-//
-// Callback structure used for asynchronous continuation of url requests when
-// invalid SSL certificates are encountered.
-//
-pub struct CefAllowCertificateErrorCallback {
-  c_object: *mut cef_allow_certificate_error_callback_t,
-}
-
-impl Clone for CefAllowCertificateErrorCallback {
-  fn clone(&self) -> CefAllowCertificateErrorCallback{
-    unsafe {
-      if !self.c_object.is_null() {
-        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
-      }
-      CefAllowCertificateErrorCallback {
-        c_object: self.c_object,
-      }
-    }
-  }
-}
-
-impl Drop for CefAllowCertificateErrorCallback {
-  fn drop(&mut self) {
-    unsafe {
-      if !self.c_object.is_null() {
-        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
-      }
-    }
-  }
-}
-
-impl CefAllowCertificateErrorCallback {
-  pub unsafe fn from_c_object(c_object: *mut cef_allow_certificate_error_callback_t) -> CefAllowCertificateErrorCallback {
-    CefAllowCertificateErrorCallback {
-      c_object: c_object,
-    }
-  }
-
-  pub unsafe fn from_c_object_addref(c_object: *mut cef_allow_certificate_error_callback_t) -> CefAllowCertificateErrorCallback {
-    if !c_object.is_null() {
-      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
-    }
-    CefAllowCertificateErrorCallback {
-      c_object: c_object,
-    }
-  }
-
-  pub fn c_object(&self) -> *mut cef_allow_certificate_error_callback_t {
-    self.c_object
-  }
-
-  pub fn c_object_addrefed(&self) -> *mut cef_allow_certificate_error_callback_t {
-    unsafe {
-      if !self.c_object.is_null() {
-        eutil::add_ref(self.c_object as *mut types::cef_base_t);
-      }
-      self.c_object
-    }
-  }
-
-  pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
-  }
-  pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
-  }
-
-  //
-  // Continue the url request. If |allow| is true (1) the request will be
-  // continued. Otherwise, the request will be canceled.
-  //
-  pub fn cont(&self, allow: libc::c_int) -> () {
-    if self.c_object.is_null() {
-      panic!("called a CEF method on a null object")
-    }
-    unsafe {
-      CefWrap::to_rust(
-        ((*self.c_object).cont.unwrap())(
-          self.c_object,
-          CefWrap::to_c(allow)))
-    }
-  }
-} 
-
-impl CefWrap<*mut cef_allow_certificate_error_callback_t> for CefAllowCertificateErrorCallback {
-  fn to_c(rust_object: CefAllowCertificateErrorCallback) -> *mut cef_allow_certificate_error_callback_t {
-    rust_object.c_object_addrefed()
-  }
-  unsafe fn to_rust(c_object: *mut cef_allow_certificate_error_callback_t) -> CefAllowCertificateErrorCallback {
-    CefAllowCertificateErrorCallback::from_c_object_addref(c_object)
-  }
-}
-impl CefWrap<*mut cef_allow_certificate_error_callback_t> for Option<CefAllowCertificateErrorCallback> {
-  fn to_c(rust_object: Option<CefAllowCertificateErrorCallback>) -> *mut cef_allow_certificate_error_callback_t {
-    match rust_object {
-      None => ptr::null_mut(),
-      Some(rust_object) => rust_object.c_object_addrefed(),
-    }
-  }
-  unsafe fn to_rust(c_object: *mut cef_allow_certificate_error_callback_t) -> Option<CefAllowCertificateErrorCallback> {
-    if c_object.is_null() {
-      None
-    } else {
-      Some(CefAllowCertificateErrorCallback::from_c_object_addref(c_object))
+      Some(CefRequestCallback::from_c_object_addref(c_object))
     }
   }
 }
@@ -372,15 +238,42 @@ pub struct _cef_request_handler_t {
       request: *mut interfaces::cef_request_t,
       is_redirect: libc::c_int) -> libc::c_int>,
 
+  //
+  // Called on the UI thread before OnBeforeBrowse in certain limited cases
+  // where navigating a new or different browser might be desirable. This
+  // includes user-initiated navigation that might open in a special way (e.g.
+  // links clicked via middle-click or ctrl + left-click) and certain types of
+  // cross-origin navigation initiated from the renderer process (e.g.
+  // navigating the top-level frame to/from a file URL). The |browser| and
+  // |frame| values represent the source of the navigation. The
+  // |target_disposition| value indicates where the user intended to navigate
+  // the browser based on standard Chromium behaviors (e.g. current tab, new
+  // tab, etc). The |user_gesture| value will be true (1) if the browser
+  // navigated via explicit user gesture (e.g. clicking a link) or false (0) if
+  // it navigated automatically (e.g. via the DomContentLoaded event). Return
+  // true (1) to cancel the navigation or false (0) to allow the navigation to
+  // proceed in the source browser's top-level frame.
+  //
+  pub on_open_urlfrom_tab: Option<extern "C" fn(
+      this: *mut cef_request_handler_t, browser: *mut interfaces::cef_browser_t,
+      frame: *mut interfaces::cef_frame_t,
+      target_url: *const types::cef_string_t,
+      target_disposition: types::cef_window_open_disposition_t,
+      user_gesture: libc::c_int) -> libc::c_int>,
+
   //
   // Called on the IO thread before a resource request is loaded. The |request|
-  // object may be modified. To cancel the request return true (1) otherwise
-  // return false (0).
+  // object may be modified. Return RV_CONTINUE to continue the request
+  // immediately. Return RV_CONTINUE_ASYNC and call cef_request_tCallback::
+  // cont() at a later time to continue or cancel the request asynchronously.
+  // Return RV_CANCEL to cancel the request immediately.
+  //
   //
   pub on_before_resource_load: Option<extern "C" fn(
       this: *mut cef_request_handler_t, browser: *mut interfaces::cef_browser_t,
       frame: *mut interfaces::cef_frame_t,
-      request: *mut interfaces::cef_request_t) -> libc::c_int>,
+      request: *mut interfaces::cef_request_t,
+      callback: *mut interfaces::cef_request_callback_t) -> types::cef_return_value_t>,
 
   //
   // Called on the IO thread before a resource is loaded. To allow the resource
@@ -394,21 +287,36 @@ pub struct _cef_request_handler_t {
       request: *mut interfaces::cef_request_t) -> *mut interfaces::cef_resource_handler_t>,
 
   //
-  // Called on the IO thread when a resource load is redirected. The |old_url|
-  // parameter will contain the old URL. The |new_url| parameter will contain
-  // the new URL and can be changed if desired.
+  // Called on the IO thread when a resource load is redirected. The |request|
+  // parameter will contain the old URL and other request-related information.
+  // The |new_url| parameter will contain the new URL and can be changed if
+  // desired. The |request| object cannot be modified in this callback.
   //
   pub on_resource_redirect: Option<extern "C" fn(
       this: *mut cef_request_handler_t, browser: *mut interfaces::cef_browser_t,
-      frame: *mut interfaces::cef_frame_t, old_url: *const types::cef_string_t,
+      frame: *mut interfaces::cef_frame_t,
+      request: *mut interfaces::cef_request_t,
       new_url: *mut types::cef_string_t) -> ()>,
 
+  //
+  // Called on the IO thread when a resource response is received. To allow the
+  // resource to load normally return false (0). To redirect or retry the
+  // resource modify |request| (url, headers or post body) and return true (1).
+  // The |response| object cannot be modified in this callback.
+  //
+  pub on_resource_response: Option<extern "C" fn(
+      this: *mut cef_request_handler_t, browser: *mut interfaces::cef_browser_t,
+      frame: *mut interfaces::cef_frame_t,
+      request: *mut interfaces::cef_request_t,
+      response: *mut interfaces::cef_response_t) -> libc::c_int>,
+
   //
   // Called on the IO thread when the browser needs credentials from the user.
   // |isProxy| indicates whether the host is a proxy server. |host| contains the
   // hostname and |port| contains the port number. Return true (1) to continue
-  // the request and call cef_auth_callback_t::cont() when the authentication
-  // information is available. Return false (0) to cancel the request.
+  // the request and call cef_auth_callback_t::cont() either in this function or
+  // at a later time when the authentication information is available. Return
+  // false (0) to cancel the request immediately.
   //
   pub get_auth_credentials: Option<extern "C" fn(
       this: *mut cef_request_handler_t, browser: *mut interfaces::cef_browser_t,
@@ -421,14 +329,15 @@ pub struct _cef_request_handler_t {
   // Called on the IO thread when JavaScript requests a specific storage quota
   // size via the webkitStorageInfo.requestQuota function. |origin_url| is the
   // origin of the page making the request. |new_size| is the requested quota
-  // size in bytes. Return true (1) and call cef_quota_callback_t::cont() either
-  // in this function or at a later time to grant or deny the request. Return
-  // false (0) to cancel the request.
+  // size in bytes. Return true (1) to continue the request and call
+  // cef_request_tCallback::cont() either in this function or at a later time to
+  // grant or deny the request. Return false (0) to cancel the request
+  // immediately.
   //
   pub on_quota_request: Option<extern "C" fn(this: *mut cef_request_handler_t,
       browser: *mut interfaces::cef_browser_t,
       origin_url: *const types::cef_string_t, new_size: i64,
-      callback: *mut interfaces::cef_quota_callback_t) -> libc::c_int>,
+      callback: *mut interfaces::cef_request_callback_t) -> libc::c_int>,
 
   //
   // Called on the UI thread to handle requests for URLs with an unknown
@@ -444,18 +353,19 @@ pub struct _cef_request_handler_t {
 
   //
   // Called on the UI thread to handle requests for URLs with an invalid SSL
-  // certificate. Return true (1) and call
-  // cef_allow_certificate_error_callback_t:: cont() either in this function or
-  // at a later time to continue or cancel the request. Return false (0) to
-  // cancel the request immediately. If |callback| is NULL the error cannot be
-  // recovered from and the request will be canceled automatically. If
-  // CefSettings.ignore_certificate_errors is set all invalid certificates will
-  // be accepted without calling this function.
+  // certificate. Return true (1) and call cef_request_tCallback::cont() either
+  // in this function or at a later time to continue or cancel the request.
+  // Return false (0) to cancel the request immediately. If |callback| is NULL
+  // the error cannot be recovered from and the request will be canceled
+  // automatically. If CefSettings.ignore_certificate_errors is set all invalid
+  // certificates will be accepted without calling this function.
   //
   pub on_certificate_error: Option<extern "C" fn(
-      this: *mut cef_request_handler_t, cert_error: types::cef_errorcode_t,
+      this: *mut cef_request_handler_t, browser: *mut interfaces::cef_browser_t,
+      cert_error: types::cef_errorcode_t,
       request_url: *const types::cef_string_t,
-      callback: *mut interfaces::cef_allow_certificate_error_callback_t) -> libc::c_int>,
+      ssl_info: *mut interfaces::cef_sslinfo_t,
+      callback: *mut interfaces::cef_request_callback_t) -> libc::c_int>,
 
   //
   // Called on the browser process IO thread before a plugin is loaded. Return
@@ -474,6 +384,15 @@ pub struct _cef_request_handler_t {
       browser: *mut interfaces::cef_browser_t,
       plugin_path: *const types::cef_string_t) -> ()>,
 
+  //
+  // Called on the browser process UI thread when the render view associated
+  // with |browser| is ready to receive/handle IPC messages in the render
+  // process.
+  //
+  pub on_render_view_ready: Option<extern "C" fn(
+      this: *mut cef_request_handler_t,
+      browser: *mut interfaces::cef_browser_t) -> ()>,
+
   //
   // Called on the browser process UI thread when the render process terminates
   // unexpectedly. |status| indicates how the process terminated.
@@ -485,13 +404,13 @@ pub struct _cef_request_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_request_handler_t = _cef_request_handler_t;
 
@@ -507,7 +426,8 @@ pub struct CefRequestHandler {
 impl Clone for CefRequestHandler {
   fn clone(&self) -> CefRequestHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestHandler {
@@ -520,7 +440,8 @@ impl Clone for CefRequestHandler {
 impl Drop for CefRequestHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -535,7 +456,8 @@ impl CefRequestHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_handler_t) -> CefRequestHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestHandler {
@@ -549,7 +471,8 @@ impl CefRequestHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -557,10 +480,10 @@ impl CefRequestHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -576,7 +499,8 @@ impl CefRequestHandler {
   pub fn on_before_browse(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       is_redirect: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -590,15 +514,55 @@ impl CefRequestHandler {
     }
   }
 
+  //
+  // Called on the UI thread before OnBeforeBrowse in certain limited cases
+  // where navigating a new or different browser might be desirable. This
+  // includes user-initiated navigation that might open in a special way (e.g.
+  // links clicked via middle-click or ctrl + left-click) and certain types of
+  // cross-origin navigation initiated from the renderer process (e.g.
+  // navigating the top-level frame to/from a file URL). The |browser| and
+  // |frame| values represent the source of the navigation. The
+  // |target_disposition| value indicates where the user intended to navigate
+  // the browser based on standard Chromium behaviors (e.g. current tab, new
+  // tab, etc). The |user_gesture| value will be true (1) if the browser
+  // navigated via explicit user gesture (e.g. clicking a link) or false (0) if
+  // it navigated automatically (e.g. via the DomContentLoaded event). Return
+  // true (1) to cancel the navigation or false (0) to allow the navigation to
+  // proceed in the source browser's top-level frame.
+  //
+  pub fn on_open_urlfrom_tab(&self, browser: interfaces::CefBrowser,
+      frame: interfaces::CefFrame, target_url: &[u16],
+      target_disposition: types::cef_window_open_disposition_t,
+      user_gesture: libc::c_int) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_open_urlfrom_tab.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser),
+          CefWrap::to_c(frame),
+          CefWrap::to_c(target_url),
+          CefWrap::to_c(target_disposition),
+          CefWrap::to_c(user_gesture)))
+    }
+  }
+
   //
   // Called on the IO thread before a resource request is loaded. The |request|
-  // object may be modified. To cancel the request return true (1) otherwise
-  // return false (0).
+  // object may be modified. Return RV_CONTINUE to continue the request
+  // immediately. Return RV_CONTINUE_ASYNC and call cef_request_tCallback::
+  // cont() at a later time to continue or cancel the request asynchronously.
+  // Return RV_CANCEL to cancel the request immediately.
+  //
   //
   pub fn on_before_resource_load(&self, browser: interfaces::CefBrowser,
-      frame: interfaces::CefFrame,
-      request: interfaces::CefRequest) -> libc::c_int {
-    if self.c_object.is_null() {
+      frame: interfaces::CefFrame, request: interfaces::CefRequest,
+      callback: interfaces::CefRequestCallback) -> types::cef_return_value_t {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -607,7 +571,8 @@ impl CefRequestHandler {
           self.c_object,
           CefWrap::to_c(browser),
           CefWrap::to_c(frame),
-          CefWrap::to_c(request)))
+          CefWrap::to_c(request),
+          CefWrap::to_c(callback)))
     }
   }
 
@@ -620,7 +585,8 @@ impl CefRequestHandler {
   pub fn get_resource_handler(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame,
       request: interfaces::CefRequest) -> interfaces::CefResourceHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -634,14 +600,16 @@ impl CefRequestHandler {
   }
 
   //
-  // Called on the IO thread when a resource load is redirected. The |old_url|
-  // parameter will contain the old URL. The |new_url| parameter will contain
-  // the new URL and can be changed if desired.
+  // Called on the IO thread when a resource load is redirected. The |request|
+  // parameter will contain the old URL and other request-related information.
+  // The |new_url| parameter will contain the new URL and can be changed if
+  // desired. The |request| object cannot be modified in this callback.
   //
   pub fn on_resource_redirect(&self, browser: interfaces::CefBrowser,
-      frame: interfaces::CefFrame, old_url: &[u16],
+      frame: interfaces::CefFrame, request: interfaces::CefRequest,
       new_url: *mut types::cef_string_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -650,23 +618,49 @@ impl CefRequestHandler {
           self.c_object,
           CefWrap::to_c(browser),
           CefWrap::to_c(frame),
-          CefWrap::to_c(old_url),
+          CefWrap::to_c(request),
           CefWrap::to_c(new_url)))
     }
   }
 
+  //
+  // Called on the IO thread when a resource response is received. To allow the
+  // resource to load normally return false (0). To redirect or retry the
+  // resource modify |request| (url, headers or post body) and return true (1).
+  // The |response| object cannot be modified in this callback.
+  //
+  pub fn on_resource_response(&self, browser: interfaces::CefBrowser,
+      frame: interfaces::CefFrame, request: interfaces::CefRequest,
+      response: interfaces::CefResponse) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_resource_response.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser),
+          CefWrap::to_c(frame),
+          CefWrap::to_c(request),
+          CefWrap::to_c(response)))
+    }
+  }
+
   //
   // Called on the IO thread when the browser needs credentials from the user.
   // |isProxy| indicates whether the host is a proxy server. |host| contains the
   // hostname and |port| contains the port number. Return true (1) to continue
-  // the request and call cef_auth_callback_t::cont() when the authentication
-  // information is available. Return false (0) to cancel the request.
+  // the request and call cef_auth_callback_t::cont() either in this function or
+  // at a later time when the authentication information is available. Return
+  // false (0) to cancel the request immediately.
   //
   pub fn get_auth_credentials(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, isProxy: libc::c_int, host: &[u16],
       port: libc::c_int, realm: &[u16], scheme: &[u16],
       callback: interfaces::CefAuthCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -688,14 +682,16 @@ impl CefRequestHandler {
   // Called on the IO thread when JavaScript requests a specific storage quota
   // size via the webkitStorageInfo.requestQuota function. |origin_url| is the
   // origin of the page making the request. |new_size| is the requested quota
-  // size in bytes. Return true (1) and call cef_quota_callback_t::cont() either
-  // in this function or at a later time to grant or deny the request. Return
-  // false (0) to cancel the request.
+  // size in bytes. Return true (1) to continue the request and call
+  // cef_request_tCallback::cont() either in this function or at a later time to
+  // grant or deny the request. Return false (0) to cancel the request
+  // immediately.
   //
   pub fn on_quota_request(&self, browser: interfaces::CefBrowser,
       origin_url: &[u16], new_size: i64,
-      callback: interfaces::CefQuotaCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+      callback: interfaces::CefRequestCallback) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -718,7 +714,8 @@ impl CefRequestHandler {
   //
   pub fn on_protocol_execution(&self, browser: interfaces::CefBrowser,
       url: &[u16], allow_os_execution: &mut libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -733,26 +730,29 @@ impl CefRequestHandler {
 
   //
   // Called on the UI thread to handle requests for URLs with an invalid SSL
-  // certificate. Return true (1) and call
-  // cef_allow_certificate_error_callback_t:: cont() either in this function or
-  // at a later time to continue or cancel the request. Return false (0) to
-  // cancel the request immediately. If |callback| is NULL the error cannot be
-  // recovered from and the request will be canceled automatically. If
-  // CefSettings.ignore_certificate_errors is set all invalid certificates will
-  // be accepted without calling this function.
+  // certificate. Return true (1) and call cef_request_tCallback::cont() either
+  // in this function or at a later time to continue or cancel the request.
+  // Return false (0) to cancel the request immediately. If |callback| is NULL
+  // the error cannot be recovered from and the request will be canceled
+  // automatically. If CefSettings.ignore_certificate_errors is set all invalid
+  // certificates will be accepted without calling this function.
   //
-  pub fn on_certificate_error(&self, cert_error: types::cef_errorcode_t,
-      request_url: &[u16],
-      callback: interfaces::CefAllowCertificateErrorCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+  pub fn on_certificate_error(&self, browser: interfaces::CefBrowser,
+      cert_error: types::cef_errorcode_t, request_url: &[u16],
+      ssl_info: interfaces::CefSSLInfo,
+      callback: interfaces::CefRequestCallback) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
       CefWrap::to_rust(
         ((*self.c_object).on_certificate_error.unwrap())(
           self.c_object,
+          CefWrap::to_c(browser),
           CefWrap::to_c(cert_error),
           CefWrap::to_c(request_url),
+          CefWrap::to_c(ssl_info),
           CefWrap::to_c(callback)))
     }
   }
@@ -764,7 +764,8 @@ impl CefRequestHandler {
   pub fn on_before_plugin_load(&self, browser: interfaces::CefBrowser,
       url: &[u16], policy_url: &[u16],
       info: interfaces::CefWebPluginInfo) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -784,7 +785,8 @@ impl CefRequestHandler {
   //
   pub fn on_plugin_crashed(&self, browser: interfaces::CefBrowser,
       plugin_path: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -796,13 +798,32 @@ impl CefRequestHandler {
     }
   }
 
+  //
+  // Called on the browser process UI thread when the render view associated
+  // with |browser| is ready to receive/handle IPC messages in the render
+  // process.
+  //
+  pub fn on_render_view_ready(&self, browser: interfaces::CefBrowser) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).on_render_view_ready.unwrap())(
+          self.c_object,
+          CefWrap::to_c(browser)))
+    }
+  }
+
   //
   // Called on the browser process UI thread when the render process terminates
   // unexpectedly. |status| indicates how the process terminated.
   //
   pub fn on_render_process_terminated(&self, browser: interfaces::CefBrowser,
       status: types::cef_termination_status_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -831,7 +852,8 @@ impl CefWrap<*mut cef_request_handler_t> for Option<CefRequestHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_handler_t) -> Option<CefRequestHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefRequestHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_resource_bundle_handler.rs b/servo/ports/cef/interfaces/cef_resource_bundle_handler.rs
index 680aa71eb693..d6501c0ea564 100644
--- a/servo/ports/cef/interfaces/cef_resource_bundle_handler.rs
+++ b/servo/ports/cef/interfaces/cef_resource_bundle_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -82,13 +83,13 @@ pub struct _cef_resource_bundle_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_resource_bundle_handler_t = _cef_resource_bundle_handler_t;
 
@@ -104,7 +105,8 @@ pub struct CefResourceBundleHandler {
 impl Clone for CefResourceBundleHandler {
   fn clone(&self) -> CefResourceBundleHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefResourceBundleHandler {
@@ -117,7 +119,8 @@ impl Clone for CefResourceBundleHandler {
 impl Drop for CefResourceBundleHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -132,7 +135,8 @@ impl CefResourceBundleHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_resource_bundle_handler_t) -> CefResourceBundleHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefResourceBundleHandler {
@@ -146,7 +150,8 @@ impl CefResourceBundleHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_resource_bundle_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -154,10 +159,10 @@ impl CefResourceBundleHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -168,7 +173,8 @@ impl CefResourceBundleHandler {
   //
   pub fn get_localized_string(&self, message_id: libc::c_int,
       string: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -191,7 +197,8 @@ impl CefResourceBundleHandler {
   pub fn get_data_resource(&self, resource_id: libc::c_int,
       data: &mut *mut libc::c_void,
       data_size: &mut libc::size_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -221,7 +228,8 @@ impl CefWrap<*mut cef_resource_bundle_handler_t> for Option<CefResourceBundleHan
     }
   }
   unsafe fn to_rust(c_object: *mut cef_resource_bundle_handler_t) -> Option<CefResourceBundleHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefResourceBundleHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_resource_handler.rs b/servo/ports/cef/interfaces/cef_resource_handler.rs
index 7f72737a86e4..a6ecd42bc2eb 100644
--- a/servo/ports/cef/interfaces/cef_resource_handler.rs
+++ b/servo/ports/cef/interfaces/cef_resource_handler.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -117,13 +118,13 @@ pub struct _cef_resource_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_resource_handler_t = _cef_resource_handler_t;
 
@@ -139,7 +140,8 @@ pub struct CefResourceHandler {
 impl Clone for CefResourceHandler {
   fn clone(&self) -> CefResourceHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefResourceHandler {
@@ -152,7 +154,8 @@ impl Clone for CefResourceHandler {
 impl Drop for CefResourceHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -167,7 +170,8 @@ impl CefResourceHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_resource_handler_t) -> CefResourceHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefResourceHandler {
@@ -181,7 +185,8 @@ impl CefResourceHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_resource_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -189,10 +194,10 @@ impl CefResourceHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -204,7 +209,8 @@ impl CefResourceHandler {
   //
   pub fn process_request(&self, request: interfaces::CefRequest,
       callback: interfaces::CefCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -229,7 +235,8 @@ impl CefResourceHandler {
   pub fn get_response_headers(&self, response: interfaces::CefResponse,
       response_length: &mut i64, redirectUrl: *mut types::cef_string_t) -> (
       ) {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -252,7 +259,8 @@ impl CefResourceHandler {
   pub fn read_response(&self, data_out: &mut (), bytes_to_read: libc::c_int,
       bytes_read: &mut libc::c_int,
       callback: interfaces::CefCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -272,7 +280,8 @@ impl CefResourceHandler {
   // cookies will be sent with the request.
   //
   pub fn can_get_cookie(&self, cookie: &interfaces::CefCookie) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -288,7 +297,8 @@ impl CefResourceHandler {
   // set or false (0) otherwise.
   //
   pub fn can_set_cookie(&self, cookie: &interfaces::CefCookie) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -303,7 +313,8 @@ impl CefResourceHandler {
   // Request processing has been canceled.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -330,7 +341,8 @@ impl CefWrap<*mut cef_resource_handler_t> for Option<CefResourceHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_resource_handler_t) -> Option<CefResourceHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefResourceHandler::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_response.rs b/servo/ports/cef/interfaces/cef_response.rs
index 86140890396c..54b455939916 100644
--- a/servo/ports/cef/interfaces/cef_response.rs
+++ b/servo/ports/cef/interfaces/cef_response.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -122,13 +123,13 @@ pub struct _cef_response_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_response_t = _cef_response_t;
 
@@ -144,7 +145,8 @@ pub struct CefResponse {
 impl Clone for CefResponse {
   fn clone(&self) -> CefResponse{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefResponse {
@@ -157,7 +159,8 @@ impl Clone for CefResponse {
 impl Drop for CefResponse {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -172,7 +175,8 @@ impl CefResponse {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_response_t) -> CefResponse {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefResponse {
@@ -186,7 +190,8 @@ impl CefResponse {
 
   pub fn c_object_addrefed(&self) -> *mut cef_response_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -194,17 +199,18 @@ impl CefResponse {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -218,7 +224,8 @@ impl CefResponse {
   // Get the response status code.
   //
   pub fn get_status(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -232,7 +239,8 @@ impl CefResponse {
   // Set the response status code.
   //
   pub fn set_status(&self, status: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -248,7 +256,8 @@ impl CefResponse {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_status_text(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -262,7 +271,8 @@ impl CefResponse {
   // Set the response status text.
   //
   pub fn set_status_text(&self, statusText: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -278,7 +288,8 @@ impl CefResponse {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_mime_type(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -292,7 +303,8 @@ impl CefResponse {
   // Set the response mime type.
   //
   pub fn set_mime_type(&self, mimeType: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -308,7 +320,8 @@ impl CefResponse {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_header(&self, name: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -323,7 +336,8 @@ impl CefResponse {
   // Get all response header fields.
   //
   pub fn get_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -338,7 +352,8 @@ impl CefResponse {
   // Set all response header fields.
   //
   pub fn set_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -377,7 +392,8 @@ impl CefWrap<*mut cef_response_t> for Option<CefResponse> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_response_t) -> Option<CefResponse> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefResponse::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_scheme.rs b/servo/ports/cef/interfaces/cef_scheme.rs
index ecbfaa70ebb4..2bf8a0030e3a 100644
--- a/servo/ports/cef/interfaces/cef_scheme.rs
+++ b/servo/ports/cef/interfaces/cef_scheme.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -108,13 +109,13 @@ pub struct _cef_scheme_registrar_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_scheme_registrar_t = _cef_scheme_registrar_t;
 
@@ -129,7 +130,8 @@ pub struct CefSchemeRegistrar {
 impl Clone for CefSchemeRegistrar {
   fn clone(&self) -> CefSchemeRegistrar{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSchemeRegistrar {
@@ -142,7 +144,8 @@ impl Clone for CefSchemeRegistrar {
 impl Drop for CefSchemeRegistrar {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -157,7 +160,8 @@ impl CefSchemeRegistrar {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_scheme_registrar_t) -> CefSchemeRegistrar {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSchemeRegistrar {
@@ -171,7 +175,8 @@ impl CefSchemeRegistrar {
 
   pub fn c_object_addrefed(&self) -> *mut cef_scheme_registrar_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -179,10 +184,10 @@ impl CefSchemeRegistrar {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -234,7 +239,8 @@ impl CefSchemeRegistrar {
   pub fn add_custom_scheme(&self, scheme_name: &[u16], is_standard: libc::c_int,
       is_local: libc::c_int,
       is_display_isolated: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -265,7 +271,8 @@ impl CefWrap<*mut cef_scheme_registrar_t> for Option<CefSchemeRegistrar> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_scheme_registrar_t) -> Option<CefSchemeRegistrar> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefSchemeRegistrar::from_c_object_addref(c_object))
@@ -303,13 +310,13 @@ pub struct _cef_scheme_handler_factory_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_scheme_handler_factory_t = _cef_scheme_handler_factory_t;
 
@@ -326,7 +333,8 @@ pub struct CefSchemeHandlerFactory {
 impl Clone for CefSchemeHandlerFactory {
   fn clone(&self) -> CefSchemeHandlerFactory{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSchemeHandlerFactory {
@@ -339,7 +347,8 @@ impl Clone for CefSchemeHandlerFactory {
 impl Drop for CefSchemeHandlerFactory {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -354,7 +363,8 @@ impl CefSchemeHandlerFactory {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_scheme_handler_factory_t) -> CefSchemeHandlerFactory {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSchemeHandlerFactory {
@@ -368,7 +378,8 @@ impl CefSchemeHandlerFactory {
 
   pub fn c_object_addrefed(&self) -> *mut cef_scheme_handler_factory_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -376,10 +387,10 @@ impl CefSchemeHandlerFactory {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -393,7 +404,8 @@ impl CefSchemeHandlerFactory {
   pub fn create(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, scheme_name: &[u16],
       request: interfaces::CefRequest) -> interfaces::CefResourceHandler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -424,7 +436,8 @@ impl CefWrap<*mut cef_scheme_handler_factory_t> for Option<CefSchemeHandlerFacto
     }
   }
   unsafe fn to_rust(c_object: *mut cef_scheme_handler_factory_t) -> Option<CefSchemeHandlerFactory> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefSchemeHandlerFactory::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_ssl_info.rs b/servo/ports/cef/interfaces/cef_ssl_info.rs
new file mode 100644
index 000000000000..d2cfcba7c59f
--- /dev/null
+++ b/servo/ports/cef/interfaces/cef_ssl_info.rs
@@ -0,0 +1,655 @@
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool and should not be edited
+// by hand. See the translator.README.txt file in the tools directory for
+// more information.
+//
+
+#![allow(non_snake_case, unused_imports)]
+
+use eutil;
+use interfaces;
+use types;
+use wrappers::CefWrap;
+
+use libc;
+use std::collections::HashMap;
+use std::mem;
+use std::ptr;
+
+//
+// Structure representing the issuer or subject field of an X.509 certificate.
+//
+#[repr(C)]
+pub struct _cef_sslcert_principal_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Returns a name that can be used to represent the issuer.  It tries in this
+  // order: CN, O and OU and returns the first non-NULL one found.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_display_name: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the common name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_common_name: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the locality name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_locality_name: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the state or province name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_state_or_province_name: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the country name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_country_name: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Retrieve the list of street addresses.
+  //
+  pub get_street_addresses: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t,
+      addresses: types::cef_string_list_t) -> ()>,
+
+  //
+  // Retrieve the list of organization names.
+  //
+  pub get_organization_names: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t, names: types::cef_string_list_t) -> (
+      )>,
+
+  //
+  // Retrieve the list of organization unit names.
+  //
+  pub get_organization_unit_names: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t, names: types::cef_string_list_t) -> (
+      )>,
+
+  //
+  // Retrieve the list of domain components.
+  //
+  pub get_domain_components: Option<extern "C" fn(
+      this: *mut cef_sslcert_principal_t,
+      components: types::cef_string_list_t) -> ()>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_sslcert_principal_t = _cef_sslcert_principal_t;
+
+
+//
+// Structure representing the issuer or subject field of an X.509 certificate.
+//
+pub struct CefSSLCertPrincipal {
+  c_object: *mut cef_sslcert_principal_t,
+}
+
+impl Clone for CefSSLCertPrincipal {
+  fn clone(&self) -> CefSSLCertPrincipal{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefSSLCertPrincipal {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefSSLCertPrincipal {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefSSLCertPrincipal {
+  pub unsafe fn from_c_object(c_object: *mut cef_sslcert_principal_t) -> CefSSLCertPrincipal {
+    CefSSLCertPrincipal {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_sslcert_principal_t) -> CefSSLCertPrincipal {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefSSLCertPrincipal {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_sslcert_principal_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_sslcert_principal_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Returns a name that can be used to represent the issuer.  It tries in this
+  // order: CN, O and OU and returns the first non-NULL one found.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_display_name(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_display_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the common name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_common_name(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_common_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the locality name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_locality_name(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_locality_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the state or province name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_state_or_province_name(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_state_or_province_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the country name.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_country_name(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_country_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Retrieve the list of street addresses.
+  //
+  pub fn get_street_addresses(&self, addresses: Vec<String>) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_street_addresses.unwrap())(
+          self.c_object,
+          CefWrap::to_c(addresses)))
+    }
+  }
+
+  //
+  // Retrieve the list of organization names.
+  //
+  pub fn get_organization_names(&self, names: Vec<String>) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_organization_names.unwrap())(
+          self.c_object,
+          CefWrap::to_c(names)))
+    }
+  }
+
+  //
+  // Retrieve the list of organization unit names.
+  //
+  pub fn get_organization_unit_names(&self, names: Vec<String>) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_organization_unit_names.unwrap())(
+          self.c_object,
+          CefWrap::to_c(names)))
+    }
+  }
+
+  //
+  // Retrieve the list of domain components.
+  //
+  pub fn get_domain_components(&self, components: Vec<String>) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_domain_components.unwrap())(
+          self.c_object,
+          CefWrap::to_c(components)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_sslcert_principal_t> for CefSSLCertPrincipal {
+  fn to_c(rust_object: CefSSLCertPrincipal) -> *mut cef_sslcert_principal_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_sslcert_principal_t) -> CefSSLCertPrincipal {
+    CefSSLCertPrincipal::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_sslcert_principal_t> for Option<CefSSLCertPrincipal> {
+  fn to_c(rust_object: Option<CefSSLCertPrincipal>) -> *mut cef_sslcert_principal_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_sslcert_principal_t) -> Option<CefSSLCertPrincipal> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefSSLCertPrincipal::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
+//
+// Structure representing SSL information.
+//
+#[repr(C)]
+pub struct _cef_sslinfo_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Returns the subject of the X.509 certificate. For HTTPS server certificates
+  // this represents the web server.  The common name of the subject should
+  // match the host name of the web server.
+  //
+  pub get_subject: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> *mut interfaces::cef_sslcert_principal_t>,
+
+  //
+  // Returns the issuer of the X.509 certificate.
+  //
+  pub get_issuer: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> *mut interfaces::cef_sslcert_principal_t>,
+
+  //
+  // Returns the DER encoded serial number for the X.509 certificate. The value
+  // possibly includes a leading 00 byte.
+  //
+  pub get_serial_number: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> *mut interfaces::cef_binary_value_t>,
+
+  //
+  // Returns the date before which the X.509 certificate is invalid.
+  // CefTime.GetTimeT() will return 0 if no date was specified.
+  //
+  pub get_valid_start: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> types::cef_time_t>,
+
+  //
+  // Returns the date after which the X.509 certificate is invalid.
+  // CefTime.GetTimeT() will return 0 if no date was specified.
+  //
+  pub get_valid_expiry: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> types::cef_time_t>,
+
+  //
+  // Returns the DER encoded data for the X.509 certificate.
+  //
+  pub get_derencoded: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> *mut interfaces::cef_binary_value_t>,
+
+  //
+  // Returns the PEM encoded data for the X.509 certificate.
+  //
+  pub get_pemencoded: Option<extern "C" fn(
+      this: *mut cef_sslinfo_t) -> *mut interfaces::cef_binary_value_t>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_sslinfo_t = _cef_sslinfo_t;
+
+
+//
+// Structure representing SSL information.
+//
+pub struct CefSSLInfo {
+  c_object: *mut cef_sslinfo_t,
+}
+
+impl Clone for CefSSLInfo {
+  fn clone(&self) -> CefSSLInfo{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefSSLInfo {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefSSLInfo {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefSSLInfo {
+  pub unsafe fn from_c_object(c_object: *mut cef_sslinfo_t) -> CefSSLInfo {
+    CefSSLInfo {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_sslinfo_t) -> CefSSLInfo {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefSSLInfo {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_sslinfo_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_sslinfo_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Returns the subject of the X.509 certificate. For HTTPS server certificates
+  // this represents the web server.  The common name of the subject should
+  // match the host name of the web server.
+  //
+  pub fn get_subject(&self) -> interfaces::CefSSLCertPrincipal {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_subject.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the issuer of the X.509 certificate.
+  //
+  pub fn get_issuer(&self) -> interfaces::CefSSLCertPrincipal {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_issuer.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the DER encoded serial number for the X.509 certificate. The value
+  // possibly includes a leading 00 byte.
+  //
+  pub fn get_serial_number(&self) -> interfaces::CefBinaryValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_serial_number.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the date before which the X.509 certificate is invalid.
+  // CefTime.GetTimeT() will return 0 if no date was specified.
+  //
+  pub fn get_valid_start(&self) -> types::cef_time_t {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_valid_start.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the date after which the X.509 certificate is invalid.
+  // CefTime.GetTimeT() will return 0 if no date was specified.
+  //
+  pub fn get_valid_expiry(&self) -> types::cef_time_t {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_valid_expiry.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the DER encoded data for the X.509 certificate.
+  //
+  pub fn get_derencoded(&self) -> interfaces::CefBinaryValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_derencoded.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the PEM encoded data for the X.509 certificate.
+  //
+  pub fn get_pemencoded(&self) -> interfaces::CefBinaryValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_pemencoded.unwrap())(
+          self.c_object))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_sslinfo_t> for CefSSLInfo {
+  fn to_c(rust_object: CefSSLInfo) -> *mut cef_sslinfo_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_sslinfo_t) -> CefSSLInfo {
+    CefSSLInfo::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_sslinfo_t> for Option<CefSSLInfo> {
+  fn to_c(rust_object: Option<CefSSLInfo>) -> *mut cef_sslinfo_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_sslinfo_t) -> Option<CefSSLInfo> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefSSLInfo::from_c_object_addref(c_object))
+    }
+  }
+}
+
diff --git a/servo/ports/cef/interfaces/cef_stream.rs b/servo/ports/cef/interfaces/cef_stream.rs
index 07dc90bdf3b7..8489931a2836 100644
--- a/servo/ports/cef/interfaces/cef_stream.rs
+++ b/servo/ports/cef/interfaces/cef_stream.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -90,13 +91,13 @@ pub struct _cef_read_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_read_handler_t = _cef_read_handler_t;
 
@@ -112,7 +113,8 @@ pub struct CefReadHandler {
 impl Clone for CefReadHandler {
   fn clone(&self) -> CefReadHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefReadHandler {
@@ -125,7 +127,8 @@ impl Clone for CefReadHandler {
 impl Drop for CefReadHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -140,7 +143,8 @@ impl CefReadHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_read_handler_t) -> CefReadHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefReadHandler {
@@ -154,7 +158,8 @@ impl CefReadHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_read_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -162,10 +167,10 @@ impl CefReadHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -173,7 +178,8 @@ impl CefReadHandler {
   //
   pub fn read(&self, ptr: &mut (), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -191,7 +197,8 @@ impl CefReadHandler {
   // SEEK_END or SEEK_SET. Return zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -207,7 +214,8 @@ impl CefReadHandler {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -221,7 +229,8 @@ impl CefReadHandler {
   // Return non-zero if at end of file.
   //
   pub fn eof(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -237,7 +246,8 @@ impl CefReadHandler {
   // the handler from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -264,7 +274,8 @@ impl CefWrap<*mut cef_read_handler_t> for Option<CefReadHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_read_handler_t) -> Option<CefReadHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefReadHandler::from_c_object_addref(c_object))
@@ -318,13 +329,13 @@ pub struct _cef_stream_reader_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_stream_reader_t = _cef_stream_reader_t;
 
@@ -340,7 +351,8 @@ pub struct CefStreamReader {
 impl Clone for CefStreamReader {
   fn clone(&self) -> CefStreamReader{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefStreamReader {
@@ -353,7 +365,8 @@ impl Clone for CefStreamReader {
 impl Drop for CefStreamReader {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -368,7 +381,8 @@ impl CefStreamReader {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_stream_reader_t) -> CefStreamReader {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefStreamReader {
@@ -382,7 +396,8 @@ impl CefStreamReader {
 
   pub fn c_object_addrefed(&self) -> *mut cef_stream_reader_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -390,10 +405,10 @@ impl CefStreamReader {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -401,7 +416,8 @@ impl CefStreamReader {
   //
   pub fn read(&self, ptr: &mut (), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -419,7 +435,8 @@ impl CefStreamReader {
   // SEEK_END or SEEK_SET. Returns zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -435,7 +452,8 @@ impl CefStreamReader {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -449,7 +467,8 @@ impl CefStreamReader {
   // Return non-zero if at end of file.
   //
   pub fn eof(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -465,7 +484,8 @@ impl CefStreamReader {
   // the reader from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -528,7 +548,8 @@ impl CefWrap<*mut cef_stream_reader_t> for Option<CefStreamReader> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_stream_reader_t) -> Option<CefStreamReader> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefStreamReader::from_c_object_addref(c_object))
@@ -583,13 +604,13 @@ pub struct _cef_write_handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_write_handler_t = _cef_write_handler_t;
 
@@ -605,7 +626,8 @@ pub struct CefWriteHandler {
 impl Clone for CefWriteHandler {
   fn clone(&self) -> CefWriteHandler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWriteHandler {
@@ -618,7 +640,8 @@ impl Clone for CefWriteHandler {
 impl Drop for CefWriteHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -633,7 +656,8 @@ impl CefWriteHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_write_handler_t) -> CefWriteHandler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWriteHandler {
@@ -647,7 +671,8 @@ impl CefWriteHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_write_handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -655,10 +680,10 @@ impl CefWriteHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -666,7 +691,8 @@ impl CefWriteHandler {
   //
   pub fn write(&self, ptr: &(), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -684,7 +710,8 @@ impl CefWriteHandler {
   // SEEK_END or SEEK_SET. Return zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -700,7 +727,8 @@ impl CefWriteHandler {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -714,7 +742,8 @@ impl CefWriteHandler {
   // Flush the stream.
   //
   pub fn flush(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -730,7 +759,8 @@ impl CefWriteHandler {
   // the handler from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -757,7 +787,8 @@ impl CefWrap<*mut cef_write_handler_t> for Option<CefWriteHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_write_handler_t) -> Option<CefWriteHandler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefWriteHandler::from_c_object_addref(c_object))
@@ -812,13 +843,13 @@ pub struct _cef_stream_writer_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_stream_writer_t = _cef_stream_writer_t;
 
@@ -834,7 +865,8 @@ pub struct CefStreamWriter {
 impl Clone for CefStreamWriter {
   fn clone(&self) -> CefStreamWriter{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefStreamWriter {
@@ -847,7 +879,8 @@ impl Clone for CefStreamWriter {
 impl Drop for CefStreamWriter {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -862,7 +895,8 @@ impl CefStreamWriter {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_stream_writer_t) -> CefStreamWriter {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefStreamWriter {
@@ -876,7 +910,8 @@ impl CefStreamWriter {
 
   pub fn c_object_addrefed(&self) -> *mut cef_stream_writer_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -884,10 +919,10 @@ impl CefStreamWriter {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -895,7 +930,8 @@ impl CefStreamWriter {
   //
   pub fn write(&self, ptr: &(), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -913,7 +949,8 @@ impl CefStreamWriter {
   // SEEK_END or SEEK_SET. Returns zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -929,7 +966,8 @@ impl CefStreamWriter {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -943,7 +981,8 @@ impl CefStreamWriter {
   // Flush the stream.
   //
   pub fn flush(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -959,7 +998,8 @@ impl CefStreamWriter {
   // the writer from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1009,7 +1049,8 @@ impl CefWrap<*mut cef_stream_writer_t> for Option<CefStreamWriter> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_stream_writer_t) -> Option<CefStreamWriter> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefStreamWriter::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_string_visitor.rs b/servo/ports/cef/interfaces/cef_string_visitor.rs
index 1e98a4f96277..f895aa706430 100644
--- a/servo/ports/cef/interfaces/cef_string_visitor.rs
+++ b/servo/ports/cef/interfaces/cef_string_visitor.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -64,13 +65,13 @@ pub struct _cef_string_visitor_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_string_visitor_t = _cef_string_visitor_t;
 
@@ -85,7 +86,8 @@ pub struct CefStringVisitor {
 impl Clone for CefStringVisitor {
   fn clone(&self) -> CefStringVisitor{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefStringVisitor {
@@ -98,7 +100,8 @@ impl Clone for CefStringVisitor {
 impl Drop for CefStringVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -113,7 +116,8 @@ impl CefStringVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_string_visitor_t) -> CefStringVisitor {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefStringVisitor {
@@ -127,7 +131,8 @@ impl CefStringVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_string_visitor_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -135,17 +140,18 @@ impl CefStringVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Method that will be executed.
   //
   pub fn visit(&self, string: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -173,7 +179,8 @@ impl CefWrap<*mut cef_string_visitor_t> for Option<CefStringVisitor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_string_visitor_t) -> Option<CefStringVisitor> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefStringVisitor::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_task.rs b/servo/ports/cef/interfaces/cef_task.rs
index 0f496a1cad50..762bcf653623 100644
--- a/servo/ports/cef/interfaces/cef_task.rs
+++ b/servo/ports/cef/interfaces/cef_task.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -68,13 +69,13 @@ pub struct _cef_task_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_task_t = _cef_task_t;
 
@@ -94,7 +95,8 @@ pub struct CefTask {
 impl Clone for CefTask {
   fn clone(&self) -> CefTask{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefTask {
@@ -107,7 +109,8 @@ impl Clone for CefTask {
 impl Drop for CefTask {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -122,7 +125,8 @@ impl CefTask {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_task_t) -> CefTask {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefTask {
@@ -136,7 +140,8 @@ impl CefTask {
 
   pub fn c_object_addrefed(&self) -> *mut cef_task_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -144,17 +149,18 @@ impl CefTask {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
   // Method that will be executed on the target thread.
   //
   pub fn execute(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -181,7 +187,8 @@ impl CefWrap<*mut cef_task_t> for Option<CefTask> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_task_t) -> Option<CefTask> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefTask::from_c_object_addref(c_object))
@@ -244,13 +251,13 @@ pub struct _cef_task_runner_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_task_runner_t = _cef_task_runner_t;
 
@@ -271,7 +278,8 @@ pub struct CefTaskRunner {
 impl Clone for CefTaskRunner {
   fn clone(&self) -> CefTaskRunner{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefTaskRunner {
@@ -284,7 +292,8 @@ impl Clone for CefTaskRunner {
 impl Drop for CefTaskRunner {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -299,7 +308,8 @@ impl CefTaskRunner {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_task_runner_t) -> CefTaskRunner {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefTaskRunner {
@@ -313,7 +323,8 @@ impl CefTaskRunner {
 
   pub fn c_object_addrefed(&self) -> *mut cef_task_runner_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -321,10 +332,10 @@ impl CefTaskRunner {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -332,7 +343,8 @@ impl CefTaskRunner {
   // |that| object.
   //
   pub fn is_same(&self, that: interfaces::CefTaskRunner) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -347,7 +359,8 @@ impl CefTaskRunner {
   // Returns true (1) if this task runner belongs to the current thread.
   //
   pub fn belongs_to_current_thread(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -362,7 +375,8 @@ impl CefTaskRunner {
   //
   pub fn belongs_to_thread(&self,
       threadId: types::cef_thread_id_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -378,7 +392,8 @@ impl CefTaskRunner {
   // Execution will occur asynchronously.
   //
   pub fn post_task(&self, task: interfaces::CefTask) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -397,7 +412,8 @@ impl CefTaskRunner {
   //
   pub fn post_delayed_task(&self, task: interfaces::CefTask,
       delay_ms: i64) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -451,7 +467,8 @@ impl CefWrap<*mut cef_task_runner_t> for Option<CefTaskRunner> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_task_runner_t) -> Option<CefTaskRunner> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefTaskRunner::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_trace.rs b/servo/ports/cef/interfaces/cef_trace.rs
index e3e0ce524a26..2a1793864bb3 100644
--- a/servo/ports/cef/interfaces/cef_trace.rs
+++ b/servo/ports/cef/interfaces/cef_trace.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -69,13 +70,13 @@ pub struct _cef_end_tracing_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_end_tracing_callback_t = _cef_end_tracing_callback_t;
 
@@ -92,7 +93,8 @@ pub struct CefEndTracingCallback {
 impl Clone for CefEndTracingCallback {
   fn clone(&self) -> CefEndTracingCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefEndTracingCallback {
@@ -105,7 +107,8 @@ impl Clone for CefEndTracingCallback {
 impl Drop for CefEndTracingCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -120,7 +123,8 @@ impl CefEndTracingCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_end_tracing_callback_t) -> CefEndTracingCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefEndTracingCallback {
@@ -134,7 +138,8 @@ impl CefEndTracingCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_end_tracing_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -142,10 +147,10 @@ impl CefEndTracingCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -154,7 +159,8 @@ impl CefEndTracingCallback {
   // deleting |tracing_file|.
   //
   pub fn on_end_tracing_complete(&self, tracing_file: &[u16]) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -182,7 +188,8 @@ impl CefWrap<*mut cef_end_tracing_callback_t> for Option<CefEndTracingCallback>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_end_tracing_callback_t) -> Option<CefEndTracingCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefEndTracingCallback::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_urlrequest.rs b/servo/ports/cef/interfaces/cef_urlrequest.rs
index e08eacc55bec..deec0bcdd6b5 100644
--- a/servo/ports/cef/interfaces/cef_urlrequest.rs
+++ b/servo/ports/cef/interfaces/cef_urlrequest.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -101,13 +102,13 @@ pub struct _cef_urlrequest_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_urlrequest_t = _cef_urlrequest_t;
 
@@ -126,7 +127,8 @@ pub struct CefURLRequest {
 impl Clone for CefURLRequest {
   fn clone(&self) -> CefURLRequest{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefURLRequest {
@@ -139,7 +141,8 @@ impl Clone for CefURLRequest {
 impl Drop for CefURLRequest {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -154,7 +157,8 @@ impl CefURLRequest {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_urlrequest_t) -> CefURLRequest {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefURLRequest {
@@ -168,7 +172,8 @@ impl CefURLRequest {
 
   pub fn c_object_addrefed(&self) -> *mut cef_urlrequest_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -176,10 +181,10 @@ impl CefURLRequest {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -187,7 +192,8 @@ impl CefURLRequest {
   // object is read-only and should not be modified.
   //
   pub fn get_request(&self) -> interfaces::CefRequest {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -201,7 +207,8 @@ impl CefURLRequest {
   // Returns the client.
   //
   pub fn get_client(&self) -> interfaces::CefURLRequestClient {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -215,7 +222,8 @@ impl CefURLRequest {
   // Returns the request status.
   //
   pub fn get_request_status(&self) -> types::cef_urlrequest_status_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -230,7 +238,8 @@ impl CefURLRequest {
   // otherwise.
   //
   pub fn get_request_error(&self) -> types::cef_errorcode_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -246,7 +255,8 @@ impl CefURLRequest {
   // The returned object is read-only and should not be modified.
   //
   pub fn get_response(&self) -> interfaces::CefResponse {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -260,7 +270,8 @@ impl CefURLRequest {
   // Cancel the request.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -280,15 +291,20 @@ impl CefURLRequest {
   // would not normally be rendered then the response may receive special
   // handling inside the browser (for example, via the file download code path
   // instead of the URL request code path). The |request| object will be marked
-  // as read-only after calling this function.
+  // as read-only after calling this function. In the browser process if
+  // |request_context| is NULL the global request context will be used. In the
+  // render process |request_context| must be NULL and the context associated
+  // with the current renderer process' browser will be used.
   //
   pub fn create(request: interfaces::CefRequest,
-      client: interfaces::CefURLRequestClient) -> interfaces::CefURLRequest {
+      client: interfaces::CefURLRequestClient,
+      request_context: interfaces::CefRequestContext) -> interfaces::CefURLRequest {
     unsafe {
       CefWrap::to_rust(
         ::urlrequest::cef_urlrequest_create(
           CefWrap::to_c(request),
-          CefWrap::to_c(client)))
+          CefWrap::to_c(client),
+          CefWrap::to_c(request_context)))
     }
   }
 } 
@@ -309,7 +325,8 @@ impl CefWrap<*mut cef_urlrequest_t> for Option<CefURLRequest> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_urlrequest_t) -> Option<CefURLRequest> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefURLRequest::from_c_object_addref(c_object))
@@ -347,8 +364,8 @@ pub struct _cef_urlrequest_client_t {
   //
   pub on_upload_progress: Option<extern "C" fn(
       this: *mut cef_urlrequest_client_t,
-      request: *mut interfaces::cef_urlrequest_t, current: u64,
-      total: u64) -> ()>,
+      request: *mut interfaces::cef_urlrequest_t, current: i64,
+      total: i64) -> ()>,
 
   //
   // Notifies the client of download progress. |current| denotes the number of
@@ -357,8 +374,8 @@ pub struct _cef_urlrequest_client_t {
   //
   pub on_download_progress: Option<extern "C" fn(
       this: *mut cef_urlrequest_client_t,
-      request: *mut interfaces::cef_urlrequest_t, current: u64,
-      total: u64) -> ()>,
+      request: *mut interfaces::cef_urlrequest_t, current: i64,
+      total: i64) -> ()>,
 
   //
   // Called when some part of the response is read. |data| contains the current
@@ -387,13 +404,13 @@ pub struct _cef_urlrequest_client_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_urlrequest_client_t = _cef_urlrequest_client_t;
 
@@ -410,7 +427,8 @@ pub struct CefURLRequestClient {
 impl Clone for CefURLRequestClient {
   fn clone(&self) -> CefURLRequestClient{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefURLRequestClient {
@@ -423,7 +441,8 @@ impl Clone for CefURLRequestClient {
 impl Drop for CefURLRequestClient {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -438,7 +457,8 @@ impl CefURLRequestClient {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_urlrequest_client_t) -> CefURLRequestClient {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefURLRequestClient {
@@ -452,7 +472,8 @@ impl CefURLRequestClient {
 
   pub fn c_object_addrefed(&self) -> *mut cef_urlrequest_client_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -460,10 +481,10 @@ impl CefURLRequestClient {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -472,7 +493,8 @@ impl CefURLRequestClient {
   // successful or not.
   //
   pub fn on_request_complete(&self, request: interfaces::CefURLRequest) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -490,8 +512,9 @@ impl CefURLRequestClient {
   // UR_FLAG_REPORT_UPLOAD_PROGRESS flag is set on the request.
   //
   pub fn on_upload_progress(&self, request: interfaces::CefURLRequest,
-      current: u64, total: u64) -> () {
-    if self.c_object.is_null() {
+      current: i64, total: i64) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -510,8 +533,9 @@ impl CefURLRequestClient {
   // response (or -1 if not determined).
   //
   pub fn on_download_progress(&self, request: interfaces::CefURLRequest,
-      current: u64, total: u64) -> () {
-    if self.c_object.is_null() {
+      current: i64, total: i64) -> () {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -531,7 +555,8 @@ impl CefURLRequestClient {
   //
   pub fn on_download_data(&self, request: interfaces::CefURLRequest, data: &(),
       data_length: libc::size_t) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -556,7 +581,8 @@ impl CefURLRequestClient {
   pub fn get_auth_credentials(&self, isProxy: libc::c_int, host: &[u16],
       port: libc::c_int, realm: &[u16], scheme: &[u16],
       callback: interfaces::CefAuthCallback) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -589,7 +615,8 @@ impl CefWrap<*mut cef_urlrequest_client_t> for Option<CefURLRequestClient> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_urlrequest_client_t) -> Option<CefURLRequestClient> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefURLRequestClient::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_v8.rs b/servo/ports/cef/interfaces/cef_v8.rs
index 8d404afe0ee6..efe234b92a38 100644
--- a/servo/ports/cef/interfaces/cef_v8.rs
+++ b/servo/ports/cef/interfaces/cef_v8.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -131,13 +132,13 @@ pub struct _cef_v8context_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8context_t = _cef_v8context_t;
 
@@ -156,7 +157,8 @@ pub struct CefV8Context {
 impl Clone for CefV8Context {
   fn clone(&self) -> CefV8Context{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Context {
@@ -169,7 +171,8 @@ impl Clone for CefV8Context {
 impl Drop for CefV8Context {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -184,7 +187,8 @@ impl CefV8Context {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8context_t) -> CefV8Context {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Context {
@@ -198,7 +202,8 @@ impl CefV8Context {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8context_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -206,10 +211,10 @@ impl CefV8Context {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -218,7 +223,8 @@ impl CefV8Context {
   // called on any render process thread.
   //
   pub fn get_task_runner(&self) -> interfaces::CefTaskRunner {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -234,7 +240,8 @@ impl CefV8Context {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -249,7 +256,8 @@ impl CefV8Context {
   // reference for WebWorker contexts.
   //
   pub fn get_browser(&self) -> interfaces::CefBrowser {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -264,7 +272,8 @@ impl CefV8Context {
   // reference for WebWorker contexts.
   //
   pub fn get_frame(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -279,7 +288,8 @@ impl CefV8Context {
   // before calling this function.
   //
   pub fn get_global(&self) -> interfaces::CefV8Value {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -297,7 +307,8 @@ impl CefV8Context {
   // if the scope was entered successfully.
   //
   pub fn enter(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -312,7 +323,8 @@ impl CefV8Context {
   // true (1) if the scope was exited successfully.
   //
   pub fn exit(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -327,7 +339,8 @@ impl CefV8Context {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefV8Context) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -346,7 +359,8 @@ impl CefV8Context {
   //
   pub fn eval(&self, code: &[u16], retval: interfaces::CefV8Value,
       exception: interfaces::CefV8Exception) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -409,7 +423,8 @@ impl CefWrap<*mut cef_v8context_t> for Option<CefV8Context> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8context_t) -> Option<CefV8Context> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8Context::from_c_object_addref(c_object))
@@ -447,13 +462,13 @@ pub struct _cef_v8handler_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8handler_t = _cef_v8handler_t;
 
@@ -470,7 +485,8 @@ pub struct CefV8Handler {
 impl Clone for CefV8Handler {
   fn clone(&self) -> CefV8Handler{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Handler {
@@ -483,7 +499,8 @@ impl Clone for CefV8Handler {
 impl Drop for CefV8Handler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -498,7 +515,8 @@ impl CefV8Handler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8handler_t) -> CefV8Handler {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Handler {
@@ -512,7 +530,8 @@ impl CefV8Handler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8handler_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -520,10 +539,10 @@ impl CefV8Handler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -537,7 +556,8 @@ impl CefV8Handler {
       arguments_count: libc::size_t, arguments: *const interfaces::CefV8Value,
       retval: interfaces::CefV8Value,
       exception: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -570,7 +590,8 @@ impl CefWrap<*mut cef_v8handler_t> for Option<CefV8Handler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8handler_t) -> Option<CefV8Handler> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8Handler::from_c_object_addref(c_object))
@@ -581,9 +602,9 @@ impl CefWrap<*mut cef_v8handler_t> for Option<CefV8Handler> {
 
 //
 // Structure that should be implemented to handle V8 accessor calls. Accessor
-// identifiers are registered by calling cef_v8value_t::set_value_byaccessor().
-// The functions of this structure will be called on the thread associated with
-// the V8 accessor.
+// identifiers are registered by calling cef_v8value_t::set_value(). The
+// functions of this structure will be called on the thread associated with the
+// V8 accessor.
 //
 #[repr(C)]
 pub struct _cef_v8accessor_t {
@@ -619,22 +640,22 @@ pub struct _cef_v8accessor_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8accessor_t = _cef_v8accessor_t;
 
 
 //
 // Structure that should be implemented to handle V8 accessor calls. Accessor
-// identifiers are registered by calling cef_v8value_t::set_value_byaccessor().
-// The functions of this structure will be called on the thread associated with
-// the V8 accessor.
+// identifiers are registered by calling cef_v8value_t::set_value(). The
+// functions of this structure will be called on the thread associated with the
+// V8 accessor.
 //
 pub struct CefV8Accessor {
   c_object: *mut cef_v8accessor_t,
@@ -643,7 +664,8 @@ pub struct CefV8Accessor {
 impl Clone for CefV8Accessor {
   fn clone(&self) -> CefV8Accessor{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Accessor {
@@ -656,7 +678,8 @@ impl Clone for CefV8Accessor {
 impl Drop for CefV8Accessor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -671,7 +694,8 @@ impl CefV8Accessor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8accessor_t) -> CefV8Accessor {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Accessor {
@@ -685,7 +709,8 @@ impl CefV8Accessor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8accessor_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -693,10 +718,10 @@ impl CefV8Accessor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -709,7 +734,8 @@ impl CefV8Accessor {
   pub fn get(&self, name: &[u16], object: interfaces::CefV8Value,
       retval: interfaces::CefV8Value,
       exception: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -733,7 +759,8 @@ impl CefV8Accessor {
   pub fn set(&self, name: &[u16], object: interfaces::CefV8Value,
       value: interfaces::CefV8Value,
       exception: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -764,7 +791,8 @@ impl CefWrap<*mut cef_v8accessor_t> for Option<CefV8Accessor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8accessor_t) -> Option<CefV8Accessor> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8Accessor::from_c_object_addref(c_object))
@@ -844,13 +872,13 @@ pub struct _cef_v8exception_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8exception_t = _cef_v8exception_t;
 
@@ -866,7 +894,8 @@ pub struct CefV8Exception {
 impl Clone for CefV8Exception {
   fn clone(&self) -> CefV8Exception{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Exception {
@@ -879,7 +908,8 @@ impl Clone for CefV8Exception {
 impl Drop for CefV8Exception {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -894,7 +924,8 @@ impl CefV8Exception {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8exception_t) -> CefV8Exception {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Exception {
@@ -908,7 +939,8 @@ impl CefV8Exception {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8exception_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -916,10 +948,10 @@ impl CefV8Exception {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -927,7 +959,8 @@ impl CefV8Exception {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_message(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -942,7 +975,8 @@ impl CefV8Exception {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_source_line(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -958,7 +992,8 @@ impl CefV8Exception {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_script_resource_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -973,7 +1008,8 @@ impl CefV8Exception {
   // line number is unknown.
   //
   pub fn get_line_number(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -988,7 +1024,8 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_start_position(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1003,7 +1040,8 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_end_position(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1018,7 +1056,8 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_start_column(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1033,7 +1072,8 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_end_column(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1060,7 +1100,8 @@ impl CefWrap<*mut cef_v8exception_t> for Option<CefV8Exception> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8exception_t) -> Option<CefV8Exception> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8Exception::from_c_object_addref(c_object))
@@ -1168,7 +1209,7 @@ pub struct _cef_v8value_t {
   pub get_int_value: Option<extern "C" fn(this: *mut cef_v8value_t) -> i32>,
 
   //
-  // Return an unsigned int value.  The underlying data will be converted to if
+  // Return an unisgned int value.  The underlying data will be converted to if
   // necessary.
   //
   pub get_uint_value: Option<extern "C" fn(this: *mut cef_v8value_t) -> u32>,
@@ -1416,13 +1457,13 @@ pub struct _cef_v8value_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8value_t = _cef_v8value_t;
 
@@ -1441,7 +1482,8 @@ pub struct CefV8Value {
 impl Clone for CefV8Value {
   fn clone(&self) -> CefV8Value{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Value {
@@ -1454,7 +1496,8 @@ impl Clone for CefV8Value {
 impl Drop for CefV8Value {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1469,7 +1512,8 @@ impl CefV8Value {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8value_t) -> CefV8Value {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Value {
@@ -1483,7 +1527,8 @@ impl CefV8Value {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8value_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1491,10 +1536,10 @@ impl CefV8Value {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -1503,7 +1548,8 @@ impl CefV8Value {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1517,7 +1563,8 @@ impl CefV8Value {
   // True if the value type is undefined.
   //
   pub fn is_undefined(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1531,7 +1578,8 @@ impl CefV8Value {
   // True if the value type is null.
   //
   pub fn is_null(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1545,7 +1593,8 @@ impl CefV8Value {
   // True if the value type is bool.
   //
   pub fn is_bool(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1559,7 +1608,8 @@ impl CefV8Value {
   // True if the value type is int.
   //
   pub fn is_int(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1573,7 +1623,8 @@ impl CefV8Value {
   // True if the value type is unsigned int.
   //
   pub fn is_uint(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1587,7 +1638,8 @@ impl CefV8Value {
   // True if the value type is double.
   //
   pub fn is_double(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1601,7 +1653,8 @@ impl CefV8Value {
   // True if the value type is Date.
   //
   pub fn is_date(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1615,7 +1668,8 @@ impl CefV8Value {
   // True if the value type is string.
   //
   pub fn is_string(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1629,7 +1683,8 @@ impl CefV8Value {
   // True if the value type is object.
   //
   pub fn is_object(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1643,7 +1698,8 @@ impl CefV8Value {
   // True if the value type is array.
   //
   pub fn is_array(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1657,7 +1713,8 @@ impl CefV8Value {
   // True if the value type is function.
   //
   pub fn is_function(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1672,7 +1729,8 @@ impl CefV8Value {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefV8Value) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1688,7 +1746,8 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_bool_value(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1703,7 +1762,8 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_int_value(&self) -> i32 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1714,11 +1774,12 @@ impl CefV8Value {
   }
 
   //
-  // Return an unsigned int value.  The underlying data will be converted to if
+  // Return an unisgned int value.  The underlying data will be converted to if
   // necessary.
   //
   pub fn get_uint_value(&self) -> u32 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1733,7 +1794,8 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_double_value(&self) -> libc::c_double {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1748,7 +1810,8 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_date_value(&self) -> types::cef_time_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1764,7 +1827,8 @@ impl CefV8Value {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string_value(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1783,7 +1847,8 @@ impl CefV8Value {
   // Returns true (1) if this is a user created object.
   //
   pub fn is_user_created(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1798,7 +1863,8 @@ impl CefV8Value {
   // attribute exists only in the scope of the current CEF value object.
   //
   pub fn has_exception(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1813,7 +1879,8 @@ impl CefV8Value {
   // exists only in the scope of the current CEF value object.
   //
   pub fn get_exception(&self) -> interfaces::CefV8Exception {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1827,7 +1894,8 @@ impl CefV8Value {
   // Clears the last exception and returns true (1) on success.
   //
   pub fn clear_exception(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1842,7 +1910,8 @@ impl CefV8Value {
   // attribute exists only in the scope of the current CEF value object.
   //
   pub fn will_rethrow_exceptions(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1860,7 +1929,8 @@ impl CefV8Value {
   // exists only in the scope of the current CEF value object.
   //
   pub fn set_rethrow_exceptions(&self, rethrow: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1875,7 +1945,8 @@ impl CefV8Value {
   // Returns true (1) if the object has a value with the specified identifier.
   //
   pub fn has_value_bykey(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1890,7 +1961,8 @@ impl CefV8Value {
   // Returns true (1) if the object has a value with the specified identifier.
   //
   pub fn has_value_byindex(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1908,7 +1980,8 @@ impl CefV8Value {
   // will return true (1) even though deletion failed.
   //
   pub fn delete_value_bykey(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1926,7 +1999,8 @@ impl CefV8Value {
   // function will return true (1) even though deletion failed.
   //
   pub fn delete_value_byindex(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1942,7 +2016,8 @@ impl CefV8Value {
   // this function is called incorrectly or an exception is thrown.
   //
   pub fn get_value_bykey(&self, key: &[u16]) -> interfaces::CefV8Value {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1959,7 +2034,8 @@ impl CefV8Value {
   //
   pub fn get_value_byindex(&self,
       index: libc::c_int) -> interfaces::CefV8Value {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1978,7 +2054,8 @@ impl CefV8Value {
   //
   pub fn set_value_bykey(&self, key: &[u16], value: interfaces::CefV8Value,
       attribute: types::cef_v8_propertyattribute_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1999,7 +2076,8 @@ impl CefV8Value {
   //
   pub fn set_value_byindex(&self, index: libc::c_int,
       value: interfaces::CefV8Value) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2021,7 +2099,8 @@ impl CefV8Value {
   pub fn set_value_byaccessor(&self, key: &[u16],
       settings: types::cef_v8_accesscontrol_t,
       attribute: types::cef_v8_propertyattribute_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2039,7 +2118,8 @@ impl CefV8Value {
   // based keys will also be returned as strings.
   //
   pub fn get_keys(&self, keys: Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2056,7 +2136,8 @@ impl CefV8Value {
   // called on user created objects.
   //
   pub fn set_user_data(&self, user_data: interfaces::CefBase) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2071,7 +2152,8 @@ impl CefV8Value {
   // Returns the user data, if any, assigned to this object.
   //
   pub fn get_user_data(&self) -> interfaces::CefBase {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2086,7 +2168,8 @@ impl CefV8Value {
   // object.
   //
   pub fn get_externally_allocated_memory(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2109,7 +2192,8 @@ impl CefV8Value {
   //
   pub fn adjust_externally_allocated_memory(&self,
       change_in_bytes: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2127,7 +2211,8 @@ impl CefV8Value {
   // Returns the number of elements in the array.
   //
   pub fn get_array_length(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2145,7 +2230,8 @@ impl CefV8Value {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_function_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2159,7 +2245,8 @@ impl CefV8Value {
   // Returns the function handler or NULL if not a CEF-created function.
   //
   pub fn get_function_handler(&self) -> interfaces::CefV8Handler {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2183,7 +2270,8 @@ impl CefV8Value {
   pub fn execute_function(&self, object: interfaces::CefV8Value,
       arguments_count: libc::size_t,
       arguments: *const interfaces::CefV8Value) -> interfaces::CefV8Value {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2207,7 +2295,8 @@ impl CefV8Value {
   pub fn execute_function_with_context(&self, context: interfaces::CefV8Context,
       object: interfaces::CefV8Value, arguments_count: libc::size_t,
       arguments: *const interfaces::CefV8Value) -> interfaces::CefV8Value {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2289,7 +2378,7 @@ impl CefV8Value {
 
   //
   // Create a new cef_v8value_t object of type Date. This function should only
-  // be called from within the scope of a cef_v8context_tHandler,
+  // be called from within the scope of a cef_render_process_handler_t,
   // cef_v8handler_t or cef_v8accessor_t callback, or in combination with
   // calling enter() and exit() on a stored cef_v8context_t reference.
   //
@@ -2315,9 +2404,9 @@ impl CefV8Value {
   //
   // Create a new cef_v8value_t object of type object with optional accessor.
   // This function should only be called from within the scope of a
-  // cef_v8context_tHandler, cef_v8handler_t or cef_v8accessor_t callback, or in
-  // combination with calling enter() and exit() on a stored cef_v8context_t
-  // reference.
+  // cef_render_process_handler_t, cef_v8handler_t or cef_v8accessor_t callback,
+  // or in combination with calling enter() and exit() on a stored
+  // cef_v8context_t reference.
   //
   pub fn create_object(
       accessor: interfaces::CefV8Accessor) -> interfaces::CefV8Value {
@@ -2332,9 +2421,9 @@ impl CefV8Value {
   // Create a new cef_v8value_t object of type array with the specified
   // |length|. If |length| is negative the returned array will have length 0.
   // This function should only be called from within the scope of a
-  // cef_v8context_tHandler, cef_v8handler_t or cef_v8accessor_t callback, or in
-  // combination with calling enter() and exit() on a stored cef_v8context_t
-  // reference.
+  // cef_render_process_handler_t, cef_v8handler_t or cef_v8accessor_t callback,
+  // or in combination with calling enter() and exit() on a stored
+  // cef_v8context_t reference.
   //
   pub fn create_array(length: libc::c_int) -> interfaces::CefV8Value {
     unsafe {
@@ -2346,7 +2435,7 @@ impl CefV8Value {
 
   //
   // Create a new cef_v8value_t object of type function. This function should
-  // only be called from within the scope of a cef_v8context_tHandler,
+  // only be called from within the scope of a cef_render_process_handler_t,
   // cef_v8handler_t or cef_v8accessor_t callback, or in combination with
   // calling enter() and exit() on a stored cef_v8context_t reference.
   //
@@ -2377,7 +2466,8 @@ impl CefWrap<*mut cef_v8value_t> for Option<CefV8Value> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8value_t) -> Option<CefV8Value> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8Value::from_c_object_addref(c_object))
@@ -2423,13 +2513,13 @@ pub struct _cef_v8stack_trace_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8stack_trace_t = _cef_v8stack_trace_t;
 
@@ -2448,7 +2538,8 @@ pub struct CefV8StackTrace {
 impl Clone for CefV8StackTrace {
   fn clone(&self) -> CefV8StackTrace{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8StackTrace {
@@ -2461,7 +2552,8 @@ impl Clone for CefV8StackTrace {
 impl Drop for CefV8StackTrace {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -2476,7 +2568,8 @@ impl CefV8StackTrace {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8stack_trace_t) -> CefV8StackTrace {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8StackTrace {
@@ -2490,7 +2583,8 @@ impl CefV8StackTrace {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8stack_trace_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -2498,10 +2592,10 @@ impl CefV8StackTrace {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -2510,7 +2604,8 @@ impl CefV8StackTrace {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2524,7 +2619,8 @@ impl CefV8StackTrace {
   // Returns the number of stack frames.
   //
   pub fn get_frame_count(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2538,7 +2634,8 @@ impl CefV8StackTrace {
   // Returns the stack frame at the specified 0-based index.
   //
   pub fn get_frame(&self, index: libc::c_int) -> interfaces::CefV8StackFrame {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2578,7 +2675,8 @@ impl CefWrap<*mut cef_v8stack_trace_t> for Option<CefV8StackTrace> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8stack_trace_t) -> Option<CefV8StackTrace> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8StackTrace::from_c_object_addref(c_object))
@@ -2660,13 +2758,13 @@ pub struct _cef_v8stack_frame_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_v8stack_frame_t = _cef_v8stack_frame_t;
 
@@ -2685,7 +2783,8 @@ pub struct CefV8StackFrame {
 impl Clone for CefV8StackFrame {
   fn clone(&self) -> CefV8StackFrame{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8StackFrame {
@@ -2698,7 +2797,8 @@ impl Clone for CefV8StackFrame {
 impl Drop for CefV8StackFrame {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -2713,7 +2813,8 @@ impl CefV8StackFrame {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8stack_frame_t) -> CefV8StackFrame {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8StackFrame {
@@ -2727,7 +2828,8 @@ impl CefV8StackFrame {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8stack_frame_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -2735,10 +2837,10 @@ impl CefV8StackFrame {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -2747,7 +2849,8 @@ impl CefV8StackFrame {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2762,7 +2865,8 @@ impl CefV8StackFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_script_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2779,7 +2883,8 @@ impl CefV8StackFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_script_name_or_source_url(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2794,7 +2899,8 @@ impl CefV8StackFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_function_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2808,7 +2914,8 @@ impl CefV8StackFrame {
   // Returns the 1-based line number for the function call or 0 if unknown.
   //
   pub fn get_line_number(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2823,7 +2930,8 @@ impl CefV8StackFrame {
   // unknown.
   //
   pub fn get_column(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2837,7 +2945,8 @@ impl CefV8StackFrame {
   // Returns true (1) if the function was compiled using eval().
   //
   pub fn is_eval(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2851,7 +2960,8 @@ impl CefV8StackFrame {
   // Returns true (1) if the function was called as a constructor via "new".
   //
   pub fn is_constructor(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2878,7 +2988,8 @@ impl CefWrap<*mut cef_v8stack_frame_t> for Option<CefV8StackFrame> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8stack_frame_t) -> Option<CefV8StackFrame> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefV8StackFrame::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_values.rs b/servo/ports/cef/interfaces/cef_values.rs
index dc9838232ccf..398ae37b782e 100644
--- a/servo/ports/cef/interfaces/cef_values.rs
+++ b/servo/ports/cef/interfaces/cef_values.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,8 +43,684 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
+//
+// Structure that wraps other data value types. Complex types (binary,
+// dictionary and list) will be referenced but not owned by this object. Can be
+// used on any process and thread.
+//
+#[repr(C)]
+pub struct _cef_value_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Returns true (1) if the underlying data is valid. This will always be true
+  // (1) for simple types. For complex types (binary, dictionary and list) the
+  // underlying data may become invalid if owned by another object (e.g. list or
+  // dictionary) and that other object is then modified or destroyed. This value
+  // object can be re-used by calling Set*() even if the underlying data is
+  // invalid.
+  //
+  pub is_valid: Option<extern "C" fn(this: *mut cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if the underlying data is owned by another object.
+  //
+  pub is_owned: Option<extern "C" fn(this: *mut cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if the underlying data is read-only. Some APIs may expose
+  // read-only objects.
+  //
+  pub is_read_only: Option<extern "C" fn(
+      this: *mut cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data. If true (1) modifications to this object will also affect |that|
+  // object and vice-versa.
+  //
+  pub is_same: Option<extern "C" fn(this: *mut cef_value_t,
+      that: *mut interfaces::cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub is_equal: Option<extern "C" fn(this: *mut cef_value_t,
+      that: *mut interfaces::cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns a copy of this object. The underlying data will also be copied.
+  //
+  pub copy: Option<extern "C" fn(
+      this: *mut cef_value_t) -> *mut interfaces::cef_value_t>,
+
+  //
+  // Returns the underlying value type.
+  //
+  pub get_type: Option<extern "C" fn(
+      this: *mut cef_value_t) -> interfaces::cef_value_type_t>,
+
+  //
+  // Returns the underlying value as type bool.
+  //
+  pub get_bool: Option<extern "C" fn(this: *mut cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns the underlying value as type int.
+  //
+  pub get_int: Option<extern "C" fn(this: *mut cef_value_t) -> libc::c_int>,
+
+  //
+  // Returns the underlying value as type double.
+  //
+  pub get_double: Option<extern "C" fn(
+      this: *mut cef_value_t) -> libc::c_double>,
+
+  //
+  // Returns the underlying value as type string.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_string: Option<extern "C" fn(
+      this: *mut cef_value_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the underlying value as type binary. The returned reference may
+  // become invalid if the value is owned by another object or if ownership is
+  // transferred to another object in the future. To maintain a reference to the
+  // value after assigning ownership to a dictionary or list pass this object to
+  // the set_value() function instead of passing the returned reference to
+  // set_binary().
+  //
+  pub get_binary: Option<extern "C" fn(
+      this: *mut cef_value_t) -> *mut interfaces::cef_binary_value_t>,
+
+  //
+  // Returns the underlying value as type dictionary. The returned reference may
+  // become invalid if the value is owned by another object or if ownership is
+  // transferred to another object in the future. To maintain a reference to the
+  // value after assigning ownership to a dictionary or list pass this object to
+  // the set_value() function instead of passing the returned reference to
+  // set_dictionary().
+  //
+  pub get_dictionary: Option<extern "C" fn(
+      this: *mut cef_value_t) -> *mut interfaces::cef_dictionary_value_t>,
+
+  //
+  // Returns the underlying value as type list. The returned reference may
+  // become invalid if the value is owned by another object or if ownership is
+  // transferred to another object in the future. To maintain a reference to the
+  // value after assigning ownership to a dictionary or list pass this object to
+  // the set_value() function instead of passing the returned reference to
+  // set_list().
+  //
+  pub get_list: Option<extern "C" fn(
+      this: *mut cef_value_t) -> *mut interfaces::cef_list_value_t>,
+
+  //
+  // Sets the underlying value as type null. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub set_null: Option<extern "C" fn(this: *mut cef_value_t) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type bool. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub set_bool: Option<extern "C" fn(this: *mut cef_value_t,
+      value: libc::c_int) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type int. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub set_int: Option<extern "C" fn(this: *mut cef_value_t,
+      value: libc::c_int) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type double. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub set_double: Option<extern "C" fn(this: *mut cef_value_t,
+      value: libc::c_double) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type string. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub set_string: Option<extern "C" fn(this: *mut cef_value_t,
+      value: *const types::cef_string_t) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type binary. Returns true (1) if the value was
+  // set successfully. This object keeps a reference to |value| and ownership of
+  // the underlying data remains unchanged.
+  //
+  pub set_binary: Option<extern "C" fn(this: *mut cef_value_t,
+      value: *mut interfaces::cef_binary_value_t) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type dict. Returns true (1) if the value was
+  // set successfully. This object keeps a reference to |value| and ownership of
+  // the underlying data remains unchanged.
+  //
+  pub set_dictionary: Option<extern "C" fn(this: *mut cef_value_t,
+      value: *mut interfaces::cef_dictionary_value_t) -> libc::c_int>,
+
+  //
+  // Sets the underlying value as type list. Returns true (1) if the value was
+  // set successfully. This object keeps a reference to |value| and ownership of
+  // the underlying data remains unchanged.
+  //
+  pub set_list: Option<extern "C" fn(this: *mut cef_value_t,
+      value: *mut interfaces::cef_list_value_t) -> libc::c_int>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  pub ref_count: u32,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+}
+
+pub type cef_value_t = _cef_value_t;
+
+
+//
+// Structure that wraps other data value types. Complex types (binary,
+// dictionary and list) will be referenced but not owned by this object. Can be
+// used on any process and thread.
+//
+pub struct CefValue {
+  c_object: *mut cef_value_t,
+}
+
+impl Clone for CefValue {
+  fn clone(&self) -> CefValue{
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefValue {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefValue {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefValue {
+  pub unsafe fn from_c_object(c_object: *mut cef_value_t) -> CefValue {
+    CefValue {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_value_t) -> CefValue {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefValue {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_value_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_value_t {
+    unsafe {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+  }
+
+  //
+  // Returns true (1) if the underlying data is valid. This will always be true
+  // (1) for simple types. For complex types (binary, dictionary and list) the
+  // underlying data may become invalid if owned by another object (e.g. list or
+  // dictionary) and that other object is then modified or destroyed. This value
+  // object can be re-used by calling Set*() even if the underlying data is
+  // invalid.
+  //
+  pub fn is_valid(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_valid.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns true (1) if the underlying data is owned by another object.
+  //
+  pub fn is_owned(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_owned.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns true (1) if the underlying data is read-only. Some APIs may expose
+  // read-only objects.
+  //
+  pub fn is_read_only(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_read_only.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data. If true (1) modifications to this object will also affect |that|
+  // object and vice-versa.
+  //
+  pub fn is_same(&self, that: interfaces::CefValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_same.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub fn is_equal(&self, that: interfaces::CefValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_equal.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
+  //
+  // Returns a copy of this object. The underlying data will also be copied.
+  //
+  pub fn copy(&self) -> interfaces::CefValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).copy.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value type.
+  //
+  pub fn get_type(&self) -> interfaces::CefValueType {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_type.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type bool.
+  //
+  pub fn get_bool(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_bool.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type int.
+  //
+  pub fn get_int(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_int.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type double.
+  //
+  pub fn get_double(&self) -> libc::c_double {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_double.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type string.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_string(&self) -> String {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_string.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type binary. The returned reference may
+  // become invalid if the value is owned by another object or if ownership is
+  // transferred to another object in the future. To maintain a reference to the
+  // value after assigning ownership to a dictionary or list pass this object to
+  // the set_value() function instead of passing the returned reference to
+  // set_binary().
+  //
+  pub fn get_binary(&self) -> interfaces::CefBinaryValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_binary.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type dictionary. The returned reference may
+  // become invalid if the value is owned by another object or if ownership is
+  // transferred to another object in the future. To maintain a reference to the
+  // value after assigning ownership to a dictionary or list pass this object to
+  // the set_value() function instead of passing the returned reference to
+  // set_dictionary().
+  //
+  pub fn get_dictionary(&self) -> interfaces::CefDictionaryValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_dictionary.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the underlying value as type list. The returned reference may
+  // become invalid if the value is owned by another object or if ownership is
+  // transferred to another object in the future. To maintain a reference to the
+  // value after assigning ownership to a dictionary or list pass this object to
+  // the set_value() function instead of passing the returned reference to
+  // set_list().
+  //
+  pub fn get_list(&self) -> interfaces::CefListValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_list.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Sets the underlying value as type null. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub fn set_null(&self) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_null.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Sets the underlying value as type bool. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub fn set_bool(&self, value: libc::c_int) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_bool.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Sets the underlying value as type int. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub fn set_int(&self, value: libc::c_int) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_int.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Sets the underlying value as type double. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub fn set_double(&self, value: libc::c_double) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_double.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Sets the underlying value as type string. Returns true (1) if the value was
+  // set successfully.
+  //
+  pub fn set_string(&self, value: &[u16]) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_string.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Sets the underlying value as type binary. Returns true (1) if the value was
+  // set successfully. This object keeps a reference to |value| and ownership of
+  // the underlying data remains unchanged.
+  //
+  pub fn set_binary(&self, value: interfaces::CefBinaryValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_binary.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Sets the underlying value as type dict. Returns true (1) if the value was
+  // set successfully. This object keeps a reference to |value| and ownership of
+  // the underlying data remains unchanged.
+  //
+  pub fn set_dictionary(&self,
+      value: interfaces::CefDictionaryValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_dictionary.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Sets the underlying value as type list. Returns true (1) if the value was
+  // set successfully. This object keeps a reference to |value| and ownership of
+  // the underlying data remains unchanged.
+  //
+  pub fn set_list(&self, value: interfaces::CefListValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_list.unwrap())(
+          self.c_object,
+          CefWrap::to_c(value)))
+    }
+  }
+
+  //
+  // Creates a new object.
+  //
+  pub fn create() -> interfaces::CefValue {
+    unsafe {
+      CefWrap::to_rust(
+        ::values::cef_value_create(
+))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_value_t> for CefValue {
+  fn to_c(rust_object: CefValue) -> *mut cef_value_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_value_t) -> CefValue {
+    CefValue::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_value_t> for Option<CefValue> {
+  fn to_c(rust_object: Option<CefValue>) -> *mut cef_value_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_value_t) -> Option<CefValue> {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
+      None
+    } else {
+      Some(CefValue::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
 //
 // Structure representing a binary value. Can be used on any process and thread.
 //
@@ -56,8 +732,10 @@ pub struct _cef_binary_value_t {
   pub base: types::cef_base_t,
 
   //
-  // Returns true (1) if this object is valid. Do not call any other functions
-  // if this function returns false (0).
+  // Returns true (1) if this object is valid. This object may become invalid if
+  // the underlying data is owned by another object (e.g. list or dictionary)
+  // and that other object is then modified or destroyed. Do not call any other
+  // functions if this function returns false (0).
   //
   pub is_valid: Option<extern "C" fn(
       this: *mut cef_binary_value_t) -> libc::c_int>,
@@ -68,6 +746,20 @@ pub struct _cef_binary_value_t {
   pub is_owned: Option<extern "C" fn(
       this: *mut cef_binary_value_t) -> libc::c_int>,
 
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data.
+  //
+  pub is_same: Option<extern "C" fn(this: *mut cef_binary_value_t,
+      that: *mut interfaces::cef_binary_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub is_equal: Option<extern "C" fn(this: *mut cef_binary_value_t,
+      that: *mut interfaces::cef_binary_value_t) -> libc::c_int>,
+
   //
   // Returns a copy of this object. The data in this object will also be copied.
   //
@@ -91,13 +783,13 @@ pub struct _cef_binary_value_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_binary_value_t = _cef_binary_value_t;
 
@@ -112,7 +804,8 @@ pub struct CefBinaryValue {
 impl Clone for CefBinaryValue {
   fn clone(&self) -> CefBinaryValue{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBinaryValue {
@@ -125,7 +818,8 @@ impl Clone for CefBinaryValue {
 impl Drop for CefBinaryValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -140,7 +834,8 @@ impl CefBinaryValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_binary_value_t) -> CefBinaryValue {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBinaryValue {
@@ -154,7 +849,8 @@ impl CefBinaryValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_binary_value_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -162,18 +858,21 @@ impl CefBinaryValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Returns true (1) if this object is valid. Do not call any other functions
-  // if this function returns false (0).
+  // Returns true (1) if this object is valid. This object may become invalid if
+  // the underlying data is owned by another object (e.g. list or dictionary)
+  // and that other object is then modified or destroyed. Do not call any other
+  // functions if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -187,7 +886,8 @@ impl CefBinaryValue {
   // Returns true (1) if this object is currently owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -197,11 +897,46 @@ impl CefBinaryValue {
     }
   }
 
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data.
+  //
+  pub fn is_same(&self, that: interfaces::CefBinaryValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_same.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub fn is_equal(&self, that: interfaces::CefBinaryValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_equal.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
   //
   // Returns a copy of this object. The data in this object will also be copied.
   //
   pub fn copy(&self) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -215,7 +950,8 @@ impl CefBinaryValue {
   // Returns the data size.
   //
   pub fn get_size(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -231,7 +967,8 @@ impl CefBinaryValue {
   //
   pub fn get_data(&self, buffer: &mut (), buffer_size: libc::size_t,
       data_offset: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -275,7 +1012,8 @@ impl CefWrap<*mut cef_binary_value_t> for Option<CefBinaryValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_binary_value_t) -> Option<CefBinaryValue> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefBinaryValue::from_c_object_addref(c_object))
@@ -296,8 +1034,10 @@ pub struct _cef_dictionary_value_t {
   pub base: types::cef_base_t,
 
   //
-  // Returns true (1) if this object is valid. Do not call any other functions
-  // if this function returns false (0).
+  // Returns true (1) if this object is valid. This object may become invalid if
+  // the underlying data is owned by another object (e.g. list or dictionary)
+  // and that other object is then modified or destroyed. Do not call any other
+  // functions if this function returns false (0).
   //
   pub is_valid: Option<extern "C" fn(
       this: *mut cef_dictionary_value_t) -> libc::c_int>,
@@ -315,6 +1055,21 @@ pub struct _cef_dictionary_value_t {
   pub is_read_only: Option<extern "C" fn(
       this: *mut cef_dictionary_value_t) -> libc::c_int>,
 
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data. If true (1) modifications to this object will also affect |that|
+  // object and vice-versa.
+  //
+  pub is_same: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
+      that: *mut interfaces::cef_dictionary_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub is_equal: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
+      that: *mut interfaces::cef_dictionary_value_t) -> libc::c_int>,
+
   //
   // Returns a writable copy of this object. If |exclude_NULL_children| is true
   // (1) any NULL dictionaries or lists will be excluded from the copy.
@@ -359,6 +1114,16 @@ pub struct _cef_dictionary_value_t {
   pub get_type: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
       key: *const types::cef_string_t) -> interfaces::cef_value_type_t>,
 
+  //
+  // Returns the value at the specified key. For simple types the returned value
+  // will copy existing data and modifications to the value will not modify this
+  // object. For complex types (binary, dictionary and list) the returned value
+  // will reference existing data and modifications to the value will modify
+  // this object.
+  //
+  pub get_value: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
+      key: *const types::cef_string_t) -> *mut interfaces::cef_value_t>,
+
   //
   // Returns the value at the specified key as type bool.
   //
@@ -385,23 +1150,40 @@ pub struct _cef_dictionary_value_t {
       key: *const types::cef_string_t) -> types::cef_string_userfree_t>,
 
   //
-  // Returns the value at the specified key as type binary.
+  // Returns the value at the specified key as type binary. The returned value
+  // will reference existing data.
   //
   pub get_binary: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
       key: *const types::cef_string_t) -> *mut interfaces::cef_binary_value_t>,
 
   //
-  // Returns the value at the specified key as type dictionary.
+  // Returns the value at the specified key as type dictionary. The returned
+  // value will reference existing data and modifications to the value will
+  // modify this object.
   //
   pub get_dictionary: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
       key: *const types::cef_string_t) -> *mut interfaces::cef_dictionary_value_t>,
 
   //
-  // Returns the value at the specified key as type list.
+  // Returns the value at the specified key as type list. The returned value
+  // will reference existing data and modifications to the value will modify
+  // this object.
   //
   pub get_list: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
       key: *const types::cef_string_t) -> *mut interfaces::cef_list_value_t>,
 
+  //
+  // Sets the value at the specified key. Returns true (1) if the value was set
+  // successfully. If |value| represents simple data then the underlying data
+  // will be copied and modifications to |value| will not modify this object. If
+  // |value| represents complex data (binary, dictionary or list) then the
+  // underlying data will be referenced and modifications to |value| will modify
+  // this object.
+  //
+  pub set_value: Option<extern "C" fn(this: *mut cef_dictionary_value_t,
+      key: *const types::cef_string_t,
+      value: *mut interfaces::cef_value_t) -> libc::c_int>,
+
   //
   // Sets the value at the specified key as type null. Returns true (1) if the
   // value was set successfully.
@@ -451,8 +1233,7 @@ pub struct _cef_dictionary_value_t {
 
   //
   // Sets the value at the specified key as type dict. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
@@ -463,8 +1244,7 @@ pub struct _cef_dictionary_value_t {
 
   //
   // Sets the value at the specified key as type list. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
@@ -476,13 +1256,13 @@ pub struct _cef_dictionary_value_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_dictionary_value_t = _cef_dictionary_value_t;
 
@@ -498,7 +1278,8 @@ pub struct CefDictionaryValue {
 impl Clone for CefDictionaryValue {
   fn clone(&self) -> CefDictionaryValue{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDictionaryValue {
@@ -511,7 +1292,8 @@ impl Clone for CefDictionaryValue {
 impl Drop for CefDictionaryValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -526,7 +1308,8 @@ impl CefDictionaryValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_dictionary_value_t) -> CefDictionaryValue {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDictionaryValue {
@@ -540,7 +1323,8 @@ impl CefDictionaryValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_dictionary_value_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -548,18 +1332,21 @@ impl CefDictionaryValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Returns true (1) if this object is valid. Do not call any other functions
-  // if this function returns false (0).
+  // Returns true (1) if this object is valid. This object may become invalid if
+  // the underlying data is owned by another object (e.g. list or dictionary)
+  // and that other object is then modified or destroyed. Do not call any other
+  // functions if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -573,7 +1360,8 @@ impl CefDictionaryValue {
   // Returns true (1) if this object is currently owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -588,7 +1376,8 @@ impl CefDictionaryValue {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -598,13 +1387,49 @@ impl CefDictionaryValue {
     }
   }
 
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data. If true (1) modifications to this object will also affect |that|
+  // object and vice-versa.
+  //
+  pub fn is_same(&self, that: interfaces::CefDictionaryValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_same.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub fn is_equal(&self, that: interfaces::CefDictionaryValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_equal.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
   //
   // Returns a writable copy of this object. If |exclude_NULL_children| is true
   // (1) any NULL dictionaries or lists will be excluded from the copy.
   //
   pub fn copy(&self,
       exclude_empty_children: libc::c_int) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -619,7 +1444,8 @@ impl CefDictionaryValue {
   // Returns the number of values.
   //
   pub fn get_size(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -633,7 +1459,8 @@ impl CefDictionaryValue {
   // Removes all values. Returns true (1) on success.
   //
   pub fn clear(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -647,7 +1474,8 @@ impl CefDictionaryValue {
   // Returns true (1) if the current dictionary has a value for the given key.
   //
   pub fn has_key(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -662,7 +1490,8 @@ impl CefDictionaryValue {
   // Reads all keys for this dictionary into the specified vector.
   //
   pub fn get_keys(&self, keys: Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -678,7 +1507,8 @@ impl CefDictionaryValue {
   // removed successfully.
   //
   pub fn remove(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -693,7 +1523,8 @@ impl CefDictionaryValue {
   // Returns the value type for the specified key.
   //
   pub fn get_type(&self, key: &[u16]) -> interfaces::CefValueType {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -704,11 +1535,32 @@ impl CefDictionaryValue {
     }
   }
 
+  //
+  // Returns the value at the specified key. For simple types the returned value
+  // will copy existing data and modifications to the value will not modify this
+  // object. For complex types (binary, dictionary and list) the returned value
+  // will reference existing data and modifications to the value will modify
+  // this object.
+  //
+  pub fn get_value(&self, key: &[u16]) -> interfaces::CefValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_value.unwrap())(
+          self.c_object,
+          CefWrap::to_c(key)))
+    }
+  }
+
   //
   // Returns the value at the specified key as type bool.
   //
   pub fn get_bool(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -723,7 +1575,8 @@ impl CefDictionaryValue {
   // Returns the value at the specified key as type int.
   //
   pub fn get_int(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -738,7 +1591,8 @@ impl CefDictionaryValue {
   // Returns the value at the specified key as type double.
   //
   pub fn get_double(&self, key: &[u16]) -> libc::c_double {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -754,7 +1608,8 @@ impl CefDictionaryValue {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string(&self, key: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -766,10 +1621,12 @@ impl CefDictionaryValue {
   }
 
   //
-  // Returns the value at the specified key as type binary.
+  // Returns the value at the specified key as type binary. The returned value
+  // will reference existing data.
   //
   pub fn get_binary(&self, key: &[u16]) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -781,10 +1638,13 @@ impl CefDictionaryValue {
   }
 
   //
-  // Returns the value at the specified key as type dictionary.
+  // Returns the value at the specified key as type dictionary. The returned
+  // value will reference existing data and modifications to the value will
+  // modify this object.
   //
   pub fn get_dictionary(&self, key: &[u16]) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -796,10 +1656,13 @@ impl CefDictionaryValue {
   }
 
   //
-  // Returns the value at the specified key as type list.
+  // Returns the value at the specified key as type list. The returned value
+  // will reference existing data and modifications to the value will modify
+  // this object.
   //
   pub fn get_list(&self, key: &[u16]) -> interfaces::CefListValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -810,12 +1673,36 @@ impl CefDictionaryValue {
     }
   }
 
+  //
+  // Sets the value at the specified key. Returns true (1) if the value was set
+  // successfully. If |value| represents simple data then the underlying data
+  // will be copied and modifications to |value| will not modify this object. If
+  // |value| represents complex data (binary, dictionary or list) then the
+  // underlying data will be referenced and modifications to |value| will modify
+  // this object.
+  //
+  pub fn set_value(&self, key: &[u16],
+      value: interfaces::CefValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_value.unwrap())(
+          self.c_object,
+          CefWrap::to_c(key),
+          CefWrap::to_c(value)))
+    }
+  }
+
   //
   // Sets the value at the specified key as type null. Returns true (1) if the
   // value was set successfully.
   //
   pub fn set_null(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -831,7 +1718,8 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_bool(&self, key: &[u16], value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -848,7 +1736,8 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_int(&self, key: &[u16], value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -865,7 +1754,8 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_double(&self, key: &[u16], value: libc::c_double) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -882,7 +1772,8 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_string(&self, key: &[u16], value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -903,7 +1794,8 @@ impl CefDictionaryValue {
   //
   pub fn set_binary(&self, key: &[u16],
       value: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -917,15 +1809,15 @@ impl CefDictionaryValue {
 
   //
   // Sets the value at the specified key as type dict. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
   //
   pub fn set_dictionary(&self, key: &[u16],
       value: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -939,15 +1831,15 @@ impl CefDictionaryValue {
 
   //
   // Sets the value at the specified key as type list. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
   //
   pub fn set_list(&self, key: &[u16],
       value: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -987,7 +1879,8 @@ impl CefWrap<*mut cef_dictionary_value_t> for Option<CefDictionaryValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_dictionary_value_t) -> Option<CefDictionaryValue> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefDictionaryValue::from_c_object_addref(c_object))
@@ -1007,8 +1900,10 @@ pub struct _cef_list_value_t {
   pub base: types::cef_base_t,
 
   //
-  // Returns true (1) if this object is valid. Do not call any other functions
-  // if this function returns false (0).
+  // Returns true (1) if this object is valid. This object may become invalid if
+  // the underlying data is owned by another object (e.g. list or dictionary)
+  // and that other object is then modified or destroyed. Do not call any other
+  // functions if this function returns false (0).
   //
   pub is_valid: Option<extern "C" fn(
       this: *mut cef_list_value_t) -> libc::c_int>,
@@ -1026,6 +1921,21 @@ pub struct _cef_list_value_t {
   pub is_read_only: Option<extern "C" fn(
       this: *mut cef_list_value_t) -> libc::c_int>,
 
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data. If true (1) modifications to this object will also affect |that|
+  // object and vice-versa.
+  //
+  pub is_same: Option<extern "C" fn(this: *mut cef_list_value_t,
+      that: *mut interfaces::cef_list_value_t) -> libc::c_int>,
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub is_equal: Option<extern "C" fn(this: *mut cef_list_value_t,
+      that: *mut interfaces::cef_list_value_t) -> libc::c_int>,
+
   //
   // Returns a writable copy of this object.
   //
@@ -1062,6 +1972,16 @@ pub struct _cef_list_value_t {
   pub get_type: Option<extern "C" fn(this: *mut cef_list_value_t,
       index: libc::c_int) -> interfaces::cef_value_type_t>,
 
+  //
+  // Returns the value at the specified index. For simple types the returned
+  // value will copy existing data and modifications to the value will not
+  // modify this object. For complex types (binary, dictionary and list) the
+  // returned value will reference existing data and modifications to the value
+  // will modify this object.
+  //
+  pub get_value: Option<extern "C" fn(this: *mut cef_list_value_t,
+      index: libc::c_int) -> *mut interfaces::cef_value_t>,
+
   //
   // Returns the value at the specified index as type bool.
   //
@@ -1088,23 +2008,39 @@ pub struct _cef_list_value_t {
       index: libc::c_int) -> types::cef_string_userfree_t>,
 
   //
-  // Returns the value at the specified index as type binary.
+  // Returns the value at the specified index as type binary. The returned value
+  // will reference existing data.
   //
   pub get_binary: Option<extern "C" fn(this: *mut cef_list_value_t,
       index: libc::c_int) -> *mut interfaces::cef_binary_value_t>,
 
   //
-  // Returns the value at the specified index as type dictionary.
+  // Returns the value at the specified index as type dictionary. The returned
+  // value will reference existing data and modifications to the value will
+  // modify this object.
   //
   pub get_dictionary: Option<extern "C" fn(this: *mut cef_list_value_t,
       index: libc::c_int) -> *mut interfaces::cef_dictionary_value_t>,
 
   //
-  // Returns the value at the specified index as type list.
+  // Returns the value at the specified index as type list. The returned value
+  // will reference existing data and modifications to the value will modify
+  // this object.
   //
   pub get_list: Option<extern "C" fn(this: *mut cef_list_value_t,
       index: libc::c_int) -> *mut interfaces::cef_list_value_t>,
 
+  //
+  // Sets the value at the specified index. Returns true (1) if the value was
+  // set successfully. If |value| represents simple data then the underlying
+  // data will be copied and modifications to |value| will not modify this
+  // object. If |value| represents complex data (binary, dictionary or list)
+  // then the underlying data will be referenced and modifications to |value|
+  // will modify this object.
+  //
+  pub set_value: Option<extern "C" fn(this: *mut cef_list_value_t,
+      index: libc::c_int, value: *mut interfaces::cef_value_t) -> libc::c_int>,
+
   //
   // Sets the value at the specified index as type null. Returns true (1) if the
   // value was set successfully.
@@ -1142,8 +2078,7 @@ pub struct _cef_list_value_t {
 
   //
   // Sets the value at the specified index as type binary. Returns true (1) if
-  // the value was set successfully. After calling this function the |value|
-  // object will no longer be valid. If |value| is currently owned by another
+  // the value was set successfully. If |value| is currently owned by another
   // object then the value will be copied and the |value| reference will not
   // change. Otherwise, ownership will be transferred to this object and the
   // |value| reference will be invalidated.
@@ -1154,8 +2089,7 @@ pub struct _cef_list_value_t {
 
   //
   // Sets the value at the specified index as type dict. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
@@ -1166,8 +2100,7 @@ pub struct _cef_list_value_t {
 
   //
   // Sets the value at the specified index as type list. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
@@ -1179,13 +2112,13 @@ pub struct _cef_list_value_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_list_value_t = _cef_list_value_t;
 
@@ -1200,7 +2133,8 @@ pub struct CefListValue {
 impl Clone for CefListValue {
   fn clone(&self) -> CefListValue{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefListValue {
@@ -1213,7 +2147,8 @@ impl Clone for CefListValue {
 impl Drop for CefListValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1228,7 +2163,8 @@ impl CefListValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_list_value_t) -> CefListValue {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefListValue {
@@ -1242,7 +2178,8 @@ impl CefListValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_list_value_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1250,18 +2187,21 @@ impl CefListValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
-  // Returns true (1) if this object is valid. Do not call any other functions
-  // if this function returns false (0).
+  // Returns true (1) if this object is valid. This object may become invalid if
+  // the underlying data is owned by another object (e.g. list or dictionary)
+  // and that other object is then modified or destroyed. Do not call any other
+  // functions if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1275,7 +2215,8 @@ impl CefListValue {
   // Returns true (1) if this object is currently owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1290,7 +2231,8 @@ impl CefListValue {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1300,11 +2242,47 @@ impl CefListValue {
     }
   }
 
+  //
+  // Returns true (1) if this object and |that| object have the same underlying
+  // data. If true (1) modifications to this object will also affect |that|
+  // object and vice-versa.
+  //
+  pub fn is_same(&self, that: interfaces::CefListValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_same.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
+  //
+  // Returns true (1) if this object and |that| object have an equivalent
+  // underlying value but are not necessarily the same object.
+  //
+  pub fn is_equal(&self, that: interfaces::CefListValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_equal.unwrap())(
+          self.c_object,
+          CefWrap::to_c(that)))
+    }
+  }
+
   //
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefListValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1319,7 +2297,8 @@ impl CefListValue {
   // value slots will default to type null. Returns true (1) on success.
   //
   pub fn set_size(&self, size: libc::size_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1334,7 +2313,8 @@ impl CefListValue {
   // Returns the number of values.
   //
   pub fn get_size(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1348,7 +2328,8 @@ impl CefListValue {
   // Removes all values. Returns true (1) on success.
   //
   pub fn clear(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1362,7 +2343,8 @@ impl CefListValue {
   // Removes the value at the specified index.
   //
   pub fn remove(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1377,7 +2359,8 @@ impl CefListValue {
   // Returns the value type at the specified index.
   //
   pub fn get_type(&self, index: libc::c_int) -> interfaces::CefValueType {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1388,11 +2371,32 @@ impl CefListValue {
     }
   }
 
+  //
+  // Returns the value at the specified index. For simple types the returned
+  // value will copy existing data and modifications to the value will not
+  // modify this object. For complex types (binary, dictionary and list) the
+  // returned value will reference existing data and modifications to the value
+  // will modify this object.
+  //
+  pub fn get_value(&self, index: libc::c_int) -> interfaces::CefValue {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_value.unwrap())(
+          self.c_object,
+          CefWrap::to_c(index)))
+    }
+  }
+
   //
   // Returns the value at the specified index as type bool.
   //
   pub fn get_bool(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1407,7 +2411,8 @@ impl CefListValue {
   // Returns the value at the specified index as type int.
   //
   pub fn get_int(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1422,7 +2427,8 @@ impl CefListValue {
   // Returns the value at the specified index as type double.
   //
   pub fn get_double(&self, index: libc::c_int) -> libc::c_double {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1438,7 +2444,8 @@ impl CefListValue {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string(&self, index: libc::c_int) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1450,10 +2457,12 @@ impl CefListValue {
   }
 
   //
-  // Returns the value at the specified index as type binary.
+  // Returns the value at the specified index as type binary. The returned value
+  // will reference existing data.
   //
   pub fn get_binary(&self, index: libc::c_int) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1465,11 +2474,14 @@ impl CefListValue {
   }
 
   //
-  // Returns the value at the specified index as type dictionary.
+  // Returns the value at the specified index as type dictionary. The returned
+  // value will reference existing data and modifications to the value will
+  // modify this object.
   //
   pub fn get_dictionary(&self,
       index: libc::c_int) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1481,10 +2493,13 @@ impl CefListValue {
   }
 
   //
-  // Returns the value at the specified index as type list.
+  // Returns the value at the specified index as type list. The returned value
+  // will reference existing data and modifications to the value will modify
+  // this object.
   //
   pub fn get_list(&self, index: libc::c_int) -> interfaces::CefListValue {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1495,12 +2510,36 @@ impl CefListValue {
     }
   }
 
+  //
+  // Sets the value at the specified index. Returns true (1) if the value was
+  // set successfully. If |value| represents simple data then the underlying
+  // data will be copied and modifications to |value| will not modify this
+  // object. If |value| represents complex data (binary, dictionary or list)
+  // then the underlying data will be referenced and modifications to |value|
+  // will modify this object.
+  //
+  pub fn set_value(&self, index: libc::c_int,
+      value: interfaces::CefValue) -> libc::c_int {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).set_value.unwrap())(
+          self.c_object,
+          CefWrap::to_c(index),
+          CefWrap::to_c(value)))
+    }
+  }
+
   //
   // Sets the value at the specified index as type null. Returns true (1) if the
   // value was set successfully.
   //
   pub fn set_null(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1517,7 +2556,8 @@ impl CefListValue {
   //
   pub fn set_bool(&self, index: libc::c_int,
       value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1534,7 +2574,8 @@ impl CefListValue {
   // value was set successfully.
   //
   pub fn set_int(&self, index: libc::c_int, value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1552,7 +2593,8 @@ impl CefListValue {
   //
   pub fn set_double(&self, index: libc::c_int,
       value: libc::c_double) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1569,7 +2611,8 @@ impl CefListValue {
   // the value was set successfully.
   //
   pub fn set_string(&self, index: libc::c_int, value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1583,15 +2626,15 @@ impl CefListValue {
 
   //
   // Sets the value at the specified index as type binary. Returns true (1) if
-  // the value was set successfully. After calling this function the |value|
-  // object will no longer be valid. If |value| is currently owned by another
+  // the value was set successfully. If |value| is currently owned by another
   // object then the value will be copied and the |value| reference will not
   // change. Otherwise, ownership will be transferred to this object and the
   // |value| reference will be invalidated.
   //
   pub fn set_binary(&self, index: libc::c_int,
       value: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1605,15 +2648,15 @@ impl CefListValue {
 
   //
   // Sets the value at the specified index as type dict. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
   //
   pub fn set_dictionary(&self, index: libc::c_int,
       value: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1627,15 +2670,15 @@ impl CefListValue {
 
   //
   // Sets the value at the specified index as type list. Returns true (1) if the
-  // value was set successfully. After calling this function the |value| object
-  // will no longer be valid. If |value| is currently owned by another object
+  // value was set successfully. If |value| is currently owned by another object
   // then the value will be copied and the |value| reference will not change.
   // Otherwise, ownership will be transferred to this object and the |value|
   // reference will be invalidated.
   //
   pub fn set_list(&self, index: libc::c_int,
       value: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1675,7 +2718,8 @@ impl CefWrap<*mut cef_list_value_t> for Option<CefListValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_list_value_t) -> Option<CefListValue> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefListValue::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_web_plugin.rs b/servo/ports/cef/interfaces/cef_web_plugin.rs
index ff13a130624b..94019e77ef53 100644
--- a/servo/ports/cef/interfaces/cef_web_plugin.rs
+++ b/servo/ports/cef/interfaces/cef_web_plugin.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -86,13 +87,13 @@ pub struct _cef_web_plugin_info_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_web_plugin_info_t = _cef_web_plugin_info_t;
 
@@ -107,7 +108,8 @@ pub struct CefWebPluginInfo {
 impl Clone for CefWebPluginInfo {
   fn clone(&self) -> CefWebPluginInfo{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWebPluginInfo {
@@ -120,7 +122,8 @@ impl Clone for CefWebPluginInfo {
 impl Drop for CefWebPluginInfo {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -135,7 +138,8 @@ impl CefWebPluginInfo {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_info_t) -> CefWebPluginInfo {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWebPluginInfo {
@@ -149,7 +153,8 @@ impl CefWebPluginInfo {
 
   pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_info_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -157,10 +162,10 @@ impl CefWebPluginInfo {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -168,7 +173,8 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -183,7 +189,8 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_path(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -198,7 +205,8 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_version(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -213,7 +221,8 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_description(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -240,7 +249,8 @@ impl CefWrap<*mut cef_web_plugin_info_t> for Option<CefWebPluginInfo> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_web_plugin_info_t) -> Option<CefWebPluginInfo> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefWebPluginInfo::from_c_object_addref(c_object))
@@ -273,13 +283,13 @@ pub struct _cef_web_plugin_info_visitor_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_web_plugin_info_visitor_t = _cef_web_plugin_info_visitor_t;
 
@@ -295,7 +305,8 @@ pub struct CefWebPluginInfoVisitor {
 impl Clone for CefWebPluginInfoVisitor {
   fn clone(&self) -> CefWebPluginInfoVisitor{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWebPluginInfoVisitor {
@@ -308,7 +319,8 @@ impl Clone for CefWebPluginInfoVisitor {
 impl Drop for CefWebPluginInfoVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -323,7 +335,8 @@ impl CefWebPluginInfoVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_info_visitor_t) -> CefWebPluginInfoVisitor {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWebPluginInfoVisitor {
@@ -337,7 +350,8 @@ impl CefWebPluginInfoVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_info_visitor_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -345,10 +359,10 @@ impl CefWebPluginInfoVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -359,7 +373,8 @@ impl CefWebPluginInfoVisitor {
   //
   pub fn visit(&self, info: interfaces::CefWebPluginInfo, count: libc::c_int,
       total: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -389,7 +404,8 @@ impl CefWrap<*mut cef_web_plugin_info_visitor_t> for Option<CefWebPluginInfoVisi
     }
   }
   unsafe fn to_rust(c_object: *mut cef_web_plugin_info_visitor_t) -> Option<CefWebPluginInfoVisitor> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefWebPluginInfoVisitor::from_c_object_addref(c_object))
@@ -421,13 +437,13 @@ pub struct _cef_web_plugin_unstable_callback_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_web_plugin_unstable_callback_t = _cef_web_plugin_unstable_callback_t;
 
@@ -443,7 +459,8 @@ pub struct CefWebPluginUnstableCallback {
 impl Clone for CefWebPluginUnstableCallback {
   fn clone(&self) -> CefWebPluginUnstableCallback{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWebPluginUnstableCallback {
@@ -456,7 +473,8 @@ impl Clone for CefWebPluginUnstableCallback {
 impl Drop for CefWebPluginUnstableCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -471,7 +489,8 @@ impl CefWebPluginUnstableCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_unstable_callback_t) -> CefWebPluginUnstableCallback {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWebPluginUnstableCallback {
@@ -485,7 +504,8 @@ impl CefWebPluginUnstableCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_unstable_callback_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -493,10 +513,10 @@ impl CefWebPluginUnstableCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -505,7 +525,8 @@ impl CefWebPluginUnstableCallback {
   // 120 seconds.
   //
   pub fn is_unstable(&self, path: &[u16], unstable: libc::c_int) -> () {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -534,7 +555,8 @@ impl CefWrap<*mut cef_web_plugin_unstable_callback_t> for Option<CefWebPluginUns
     }
   }
   unsafe fn to_rust(c_object: *mut cef_web_plugin_unstable_callback_t) -> Option<CefWebPluginUnstableCallback> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefWebPluginUnstableCallback::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_xml_reader.rs b/servo/ports/cef/interfaces/cef_xml_reader.rs
index ed79167e9283..485ef4c2ee7f 100644
--- a/servo/ports/cef/interfaces/cef_xml_reader.rs
+++ b/servo/ports/cef/interfaces/cef_xml_reader.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -277,13 +278,13 @@ pub struct _cef_xml_reader_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_xml_reader_t = _cef_xml_reader_t;
 
@@ -300,7 +301,8 @@ pub struct CefXmlReader {
 impl Clone for CefXmlReader {
   fn clone(&self) -> CefXmlReader{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefXmlReader {
@@ -313,7 +315,8 @@ impl Clone for CefXmlReader {
 impl Drop for CefXmlReader {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -328,7 +331,8 @@ impl CefXmlReader {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_xml_reader_t) -> CefXmlReader {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefXmlReader {
@@ -342,7 +346,8 @@ impl CefXmlReader {
 
   pub fn c_object_addrefed(&self) -> *mut cef_xml_reader_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -350,10 +355,10 @@ impl CefXmlReader {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -362,7 +367,8 @@ impl CefXmlReader {
   // if the cursor position was set successfully.
   //
   pub fn move_to_next_node(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -377,7 +383,8 @@ impl CefXmlReader {
   // occurs on the correct thread.
   //
   pub fn close(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -391,7 +398,8 @@ impl CefXmlReader {
   // Returns true (1) if an error has been reported by the XML parser.
   //
   pub fn has_error(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -406,7 +414,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_error(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -424,7 +433,8 @@ impl CefXmlReader {
   // Returns the node type.
   //
   pub fn get_type(&self) -> types::cef_xml_node_type_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -438,7 +448,8 @@ impl CefXmlReader {
   // Returns the node depth. Depth starts at 0 for the root node.
   //
   pub fn get_depth(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -454,7 +465,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_local_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -470,7 +482,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_prefix(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -486,7 +499,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_qualified_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -502,7 +516,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_namespace_uri(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -518,7 +533,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_base_uri(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -534,7 +550,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_xml_lang(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -549,7 +566,8 @@ impl CefXmlReader {
   // NULL but <a></a> is not.
   //
   pub fn is_empty_element(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -563,7 +581,8 @@ impl CefXmlReader {
   // Returns true (1) if the node has a text value.
   //
   pub fn has_value(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -578,7 +597,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_value(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -592,7 +612,8 @@ impl CefXmlReader {
   // Returns true (1) if the node has attributes.
   //
   pub fn has_attributes(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -606,7 +627,8 @@ impl CefXmlReader {
   // Returns the number of attributes.
   //
   pub fn get_attribute_count(&self) -> libc::size_t {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -621,7 +643,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_attribute_byindex(&self, index: libc::c_int) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -637,7 +660,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_attribute_byqname(&self, qualifiedName: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -655,7 +679,8 @@ impl CefXmlReader {
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_attribute_bylname(&self, localName: &[u16],
       namespaceURI: &[u16]) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -672,7 +697,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_inner_xml(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -687,7 +713,8 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_outer_xml(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -701,7 +728,8 @@ impl CefXmlReader {
   // Returns the line number for the current node.
   //
   pub fn get_line_number(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -722,7 +750,8 @@ impl CefXmlReader {
   // true (1) if the cursor position was set successfully.
   //
   pub fn move_to_attribute_byindex(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -739,7 +768,8 @@ impl CefXmlReader {
   //
   pub fn move_to_attribute_byqname(&self,
       qualifiedName: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -757,7 +787,8 @@ impl CefXmlReader {
   //
   pub fn move_to_attribute_bylname(&self, localName: &[u16],
       namespaceURI: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -774,7 +805,8 @@ impl CefXmlReader {
   // true (1) if the cursor position was set successfully.
   //
   pub fn move_to_first_attribute(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -789,7 +821,8 @@ impl CefXmlReader {
   // (1) if the cursor position was set successfully.
   //
   pub fn move_to_next_attribute(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -804,7 +837,8 @@ impl CefXmlReader {
   // cursor position was set successfully.
   //
   pub fn move_to_carrying_element(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -847,7 +881,8 @@ impl CefWrap<*mut cef_xml_reader_t> for Option<CefXmlReader> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_xml_reader_t) -> Option<CefXmlReader> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefXmlReader::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/cef_zip_reader.rs b/servo/ports/cef/interfaces/cef_zip_reader.rs
index 15c0527a0018..fa68644de814 100644
--- a/servo/ports/cef/interfaces/cef_zip_reader.rs
+++ b/servo/ports/cef/interfaces/cef_zip_reader.rs
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+// Copyright (c) 2015 Marshall A. Greenblatt. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -43,6 +43,7 @@ use wrappers::CefWrap;
 
 use libc;
 use std::collections::HashMap;
+use std::mem;
 use std::ptr;
 
 //
@@ -105,7 +106,7 @@ pub struct _cef_zip_reader_t {
   // Returns the last modified timestamp for the file.
   //
   pub get_file_last_modified: Option<extern "C" fn(
-      this: *mut cef_zip_reader_t) -> libc::time_t>,
+      this: *mut cef_zip_reader_t) -> types::cef_time_t>,
 
   //
   // Opens the file for reading of uncompressed data. A read password may
@@ -140,13 +141,13 @@ pub struct _cef_zip_reader_t {
   //
   // The reference count. This will only be present for Rust instances!
   //
-  pub ref_count: usize,
+  pub ref_count: u32,
 
   //
   // Extra data. This will only be present for Rust instances!
   //
   pub extra: u8,
-} 
+}
 
 pub type cef_zip_reader_t = _cef_zip_reader_t;
 
@@ -163,7 +164,8 @@ pub struct CefZipReader {
 impl Clone for CefZipReader {
   fn clone(&self) -> CefZipReader{
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefZipReader {
@@ -176,7 +178,8 @@ impl Clone for CefZipReader {
 impl Drop for CefZipReader {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -191,7 +194,8 @@ impl CefZipReader {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_zip_reader_t) -> CefZipReader {
-    if !c_object.is_null() {
+    if !c_object.is_null() &&
+        c_object as usize != mem::POST_DROP_USIZE {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefZipReader {
@@ -205,7 +209,8 @@ impl CefZipReader {
 
   pub fn c_object_addrefed(&self) -> *mut cef_zip_reader_t {
     unsafe {
-      if !self.c_object.is_null() {
+      if !self.c_object.is_null() &&
+          self.c_object as usize != mem::POST_DROP_USIZE {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -213,10 +218,10 @@ impl CefZipReader {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null()
+    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null()
+    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
   }
 
   //
@@ -224,7 +229,8 @@ impl CefZipReader {
   // cursor position was set successfully.
   //
   pub fn move_to_first_file(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -239,7 +245,8 @@ impl CefZipReader {
   // cursor position was set successfully.
   //
   pub fn move_to_next_file(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -256,7 +263,8 @@ impl CefZipReader {
   //
   pub fn move_to_file(&self, fileName: &[u16],
       caseSensitive: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -273,7 +281,8 @@ impl CefZipReader {
   // occurs on the correct thread.
   //
   pub fn close(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,7 +300,8 @@ impl CefZipReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_file_name(&self) -> String {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -305,7 +315,8 @@ impl CefZipReader {
   // Returns the uncompressed size of the file.
   //
   pub fn get_file_size(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -318,8 +329,9 @@ impl CefZipReader {
   //
   // Returns the last modified timestamp for the file.
   //
-  pub fn get_file_last_modified(&self) -> libc::time_t {
-    if self.c_object.is_null() {
+  pub fn get_file_last_modified(&self) -> types::cef_time_t {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -334,7 +346,8 @@ impl CefZipReader {
   // optionally be specified.
   //
   pub fn open_file(&self, password: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -349,7 +362,8 @@ impl CefZipReader {
   // Closes the file.
   //
   pub fn close_file(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -365,7 +379,8 @@ impl CefZipReader {
   //
   pub fn read_file(&self, buffer: &mut (),
       bufferSize: libc::size_t) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -381,7 +396,8 @@ impl CefZipReader {
   // Returns the current offset in the uncompressed file contents.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -395,7 +411,8 @@ impl CefZipReader {
   // Returns true (1) if at end of the file contents.
   //
   pub fn eof(&self) -> libc::c_int {
-    if self.c_object.is_null() {
+    if self.c_object.is_null() ||
+       self.c_object as usize == mem::POST_DROP_USIZE {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -435,7 +452,8 @@ impl CefWrap<*mut cef_zip_reader_t> for Option<CefZipReader> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_zip_reader_t) -> Option<CefZipReader> {
-    if c_object.is_null() {
+    if c_object.is_null() &&
+       c_object as usize != mem::POST_DROP_USIZE {
       None
     } else {
       Some(CefZipReader::from_c_object_addref(c_object))
diff --git a/servo/ports/cef/interfaces/mod.rs b/servo/ports/cef/interfaces/mod.rs
index 7080eed9fdd1..19177845e019 100644
--- a/servo/ports/cef/interfaces/mod.rs
+++ b/servo/ports/cef/interfaces/mod.rs
@@ -2,104 +2,69 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-//! This file is currently *not* autogenerated, but maybe it should be. (It's a little complicated
-//! because we need to reexport a bunch of types in `types.rs`.)
+pub use interfaces::cef_app::{CefApp,cef_app_t,};
+pub use interfaces::cef_auth_callback::{CefAuthCallback,cef_auth_callback_t,};
+pub use interfaces::cef_browser_process_handler::{CefBrowserProcessHandler,cef_browser_process_handler_t,};
+pub use interfaces::cef_browser::{CefBrowser,CefRunFileDialogCallback,CefNavigationEntryVisitor,CefBrowserHost,cef_browser_t,cef_run_file_dialog_callback_t,cef_navigation_entry_visitor_t,cef_browser_host_t,};
+pub use interfaces::cef_callback::{CefCallback,CefCompletionCallback,cef_callback_t,cef_completion_callback_t,};
+pub use interfaces::cef_client::{CefClient,cef_client_t,};
+pub use interfaces::cef_command_line::{CefCommandLine,cef_command_line_t,};
+pub use interfaces::cef_context_menu_handler::{CefContextMenuHandler,CefContextMenuParams,cef_context_menu_handler_t,cef_context_menu_params_t,};
+pub use interfaces::cef_cookie::{CefCookieManager,CefCookieVisitor,CefSetCookieCallback,CefDeleteCookiesCallback,cef_cookie_manager_t,cef_cookie_visitor_t,cef_set_cookie_callback_t,cef_delete_cookies_callback_t,};
+pub use interfaces::cef_dialog_handler::{CefFileDialogCallback,CefDialogHandler,cef_file_dialog_callback_t,cef_dialog_handler_t,};
+pub use interfaces::cef_display_handler::{CefDisplayHandler,cef_display_handler_t,};
+pub use interfaces::cef_dom::{CefDOMVisitor,CefDOMDocument,CefDOMNode,cef_domvisitor_t,cef_domdocument_t,cef_domnode_t,};
+pub use interfaces::cef_download_handler::{CefBeforeDownloadCallback,CefDownloadItemCallback,CefDownloadHandler,cef_before_download_callback_t,cef_download_item_callback_t,cef_download_handler_t,};
+pub use interfaces::cef_download_item::{CefDownloadItem,cef_download_item_t,};
+pub use interfaces::cef_drag_data::{CefDragData,cef_drag_data_t,};
+pub use interfaces::cef_drag_handler::{CefDragHandler,cef_drag_handler_t,};
+pub use interfaces::cef_find_handler::{CefFindHandler,cef_find_handler_t,};
+pub use interfaces::cef_focus_handler::{CefFocusHandler,cef_focus_handler_t,};
+pub use interfaces::cef_frame::{CefFrame,cef_frame_t,};
+pub use interfaces::cef_geolocation_handler::{CefGeolocationCallback,CefGeolocationHandler,cef_geolocation_callback_t,cef_geolocation_handler_t,};
+pub use interfaces::cef_geolocation::{CefGetGeolocationCallback,cef_get_geolocation_callback_t,};
+pub use interfaces::cef_jsdialog_handler::{CefJSDialogCallback,CefJSDialogHandler,cef_jsdialog_callback_t,cef_jsdialog_handler_t,};
+pub use interfaces::cef_keyboard_handler::{CefKeyboardHandler,cef_keyboard_handler_t,};
+pub use interfaces::cef_life_span_handler::{CefLifeSpanHandler,cef_life_span_handler_t,};
+pub use interfaces::cef_load_handler::{CefLoadHandler,cef_load_handler_t,};
+pub use interfaces::cef_menu_model::{CefMenuModel,cef_menu_model_t,};
+pub use interfaces::cef_navigation_entry::{CefNavigationEntry,cef_navigation_entry_t,};
+pub use interfaces::cef_origin_whitelist::{};
+pub use interfaces::cef_parser::{};
+pub use interfaces::cef_path_util::{};
+pub use interfaces::cef_print_handler::{CefPrintDialogCallback,CefPrintJobCallback,CefPrintHandler,cef_print_dialog_callback_t,cef_print_job_callback_t,cef_print_handler_t,};
+pub use interfaces::cef_print_settings::{CefPrintSettings,cef_print_settings_t,};
+pub use interfaces::cef_process_message::{CefProcessMessage,cef_process_message_t,};
+pub use interfaces::cef_process_util::{};
+pub use interfaces::cef_render_handler::{CefRenderHandler,cef_render_handler_t,};
+pub use interfaces::cef_render_process_handler::{CefRenderProcessHandler,cef_render_process_handler_t,};
+pub use interfaces::cef_request_context_handler::{CefRequestContextHandler,cef_request_context_handler_t,};
+pub use interfaces::cef_request_context::{CefRequestContext,cef_request_context_t,};
+pub use interfaces::cef_request_handler::{CefRequestCallback,CefRequestHandler,cef_request_callback_t,cef_request_handler_t,};
+pub use interfaces::cef_request::{CefRequest,CefPostData,CefPostDataElement,cef_request_t,cef_post_data_t,cef_post_data_element_t,};
+pub use interfaces::cef_resource_bundle_handler::{CefResourceBundleHandler,cef_resource_bundle_handler_t,};
+pub use interfaces::cef_resource_handler::{CefResourceHandler,cef_resource_handler_t,};
+pub use interfaces::cef_response::{CefResponse,cef_response_t,};
+pub use interfaces::cef_scheme::{CefSchemeRegistrar,CefSchemeHandlerFactory,cef_scheme_registrar_t,cef_scheme_handler_factory_t,};
+pub use interfaces::cef_ssl_info::{CefSSLCertPrincipal,CefSSLInfo,cef_sslcert_principal_t,cef_sslinfo_t,};
+pub use interfaces::cef_stream::{CefReadHandler,CefStreamReader,CefWriteHandler,CefStreamWriter,cef_read_handler_t,cef_stream_reader_t,cef_write_handler_t,cef_stream_writer_t,};
+pub use interfaces::cef_string_visitor::{CefStringVisitor,cef_string_visitor_t,};
+pub use interfaces::cef_task::{CefTask,CefTaskRunner,cef_task_t,cef_task_runner_t,};
+pub use interfaces::cef_trace::{CefEndTracingCallback,cef_end_tracing_callback_t,};
+pub use interfaces::cef_urlrequest::{CefURLRequest,CefURLRequestClient,cef_urlrequest_t,cef_urlrequest_client_t,};
+pub use interfaces::cef_v8::{CefV8Context,CefV8Handler,CefV8Accessor,CefV8Exception,CefV8Value,CefV8StackTrace,CefV8StackFrame,cef_v8context_t,cef_v8handler_t,cef_v8accessor_t,cef_v8exception_t,cef_v8value_t,cef_v8stack_trace_t,cef_v8stack_frame_t,};
+pub use interfaces::cef_values::{CefValue,CefBinaryValue,CefDictionaryValue,CefListValue,cef_value_t,cef_binary_value_t,cef_dictionary_value_t,cef_list_value_t,};
+pub use interfaces::cef_web_plugin::{CefWebPluginInfo,CefWebPluginInfoVisitor,CefWebPluginUnstableCallback,cef_web_plugin_info_t,cef_web_plugin_info_visitor_t,cef_web_plugin_unstable_callback_t,};
+pub use interfaces::cef_xml_reader::{CefXmlReader,cef_xml_reader_t,};
+pub use interfaces::cef_zip_reader::{CefZipReader,cef_zip_reader_t,};
+pub use types::{cef_window_handle_t,cef_cursor_handle_t,cef_string_t,cef_string_userfree_t,cef_string_utf8_t,cef_string_userfree_utf8_t,cef_string_utf16_t,cef_string_userfree_utf16_t,cef_string_wide_t,cef_string_userfree_wide_t,cef_main_args_t,cef_color_t,cef_mouse_event_t,CefMouseEvent,cef_key_event_t,CefKeyEvent,cef_point_t,CefValueType,CefProcessId,cef_settings_t,cef_base_t,CefBase,cef_window_info_t,CefWindowInfo,cef_time_t,cef_size_t,cef_page_range_t,cef_geoposition_t,CefGeoposition,cef_cookie_t,CefCookie,cef_popup_features_t,CefPopupFeatures,cef_screen_info_t,CefScreenInfo,cef_browser_settings_t,CefBrowserSettings,cef_cursor_info_t,CefCursorInfo,cef_request_context_settings_t,CefRequestContextSettings,cef_string_map_t,cef_string_multimap_t,cef_string_list_t,cef_text_input_context_t,cef_event_handle_t,cef_state_t,cef_thread_id_t,cef_navigation_type_t,cef_mouse_button_type_t,cef_postdataelement_type_t,cef_urlrequest_flags_t,cef_urlrequest_status_t,cef_errorcode_t,cef_key_event_type_t,cef_paint_element_type_t,cef_dom_document_type_t,cef_file_dialog_mode_t,cef_value_type_t,cef_process_id_t,cef_log_severity_t,cef_menu_item_type_t,cef_context_menu_type_flags_t,cef_context_menu_media_type_t,cef_context_menu_media_state_flags_t,cef_context_menu_edit_state_flags_t,cef_event_flags_t,cef_dom_event_phase_t,cef_dom_node_type_t,cef_focus_source_t,cef_jsdialog_type_t,cef_duplex_mode_t,cef_color_model_t,cef_resource_type_t,cef_transition_type_t,cef_termination_status_t,cef_v8_accesscontrol_t,cef_v8_propertyattribute_t,cef_xml_node_type_t,cef_geoposition_error_code_t,cef_drag_operations_mask_t,cef_xml_encoding_type_t,cef_window_open_disposition_t,cef_cursor_type_t,cef_return_value_t,};
+
 
-pub use interfaces::cef_app::{CefApp, cef_app_t};
-pub use interfaces::cef_auth_callback::{CefAuthCallback, cef_auth_callback_t};
-pub use interfaces::cef_browser::{CefBrowser, CefBrowserHost, CefRunFileDialogCallback};
-pub use interfaces::cef_browser::{cef_browser_host_t, cef_browser_t};
-pub use interfaces::cef_browser::{cef_run_file_dialog_callback_t};
-pub use interfaces::cef_browser_process_handler::{CefBrowserProcessHandler};
-pub use interfaces::cef_browser_process_handler::{cef_browser_process_handler_t};
-pub use interfaces::cef_callback::{CefCallback, CefCompletionCallback, cef_callback_t};
-pub use interfaces::cef_callback::{cef_completion_callback_t};
-pub use interfaces::cef_client::{CefClient, cef_client_t};
-pub use interfaces::cef_command_line::{CefCommandLine, cef_command_line_t};
-pub use interfaces::cef_context_menu_handler::{CefContextMenuHandler, CefContextMenuParams};
-pub use interfaces::cef_context_menu_handler::{cef_context_menu_handler_t};
-pub use interfaces::cef_context_menu_handler::{cef_context_menu_params_t};
-pub use interfaces::cef_cookie::{CefCookieManager, CefCookieVisitor, cef_cookie_manager_t};
-pub use interfaces::cef_cookie::{cef_cookie_visitor_t};
-pub use interfaces::cef_dialog_handler::{CefDialogHandler, CefFileDialogCallback};
-pub use interfaces::cef_dialog_handler::{cef_dialog_handler_t, cef_file_dialog_callback_t};
-pub use interfaces::cef_display_handler::{CefDisplayHandler, cef_display_handler_t};
-pub use interfaces::cef_dom::{CefDOMDocument, CefDOMNode, CefDOMVisitor, cef_domdocument_t};
-pub use interfaces::cef_dom::{cef_domnode_t, cef_domvisitor_t};
-pub use interfaces::cef_download_handler::{CefBeforeDownloadCallback, CefDownloadHandler};
-pub use interfaces::cef_download_handler::{CefDownloadItemCallback};
-pub use interfaces::cef_download_handler::{cef_before_download_callback_t};
-pub use interfaces::cef_download_handler::{cef_download_handler_t, cef_download_item_callback_t};
-pub use interfaces::cef_download_item::{CefDownloadItem, cef_download_item_t};
-pub use interfaces::cef_drag_data::{CefDragData, cef_drag_data_t};
-pub use interfaces::cef_drag_handler::{CefDragHandler, cef_drag_handler_t};
-pub use interfaces::cef_focus_handler::{CefFocusHandler, cef_focus_handler_t};
-pub use interfaces::cef_frame::{CefFrame, cef_frame_t};
-pub use interfaces::cef_geolocation::{CefGetGeolocationCallback, cef_get_geolocation_callback_t};
-pub use interfaces::cef_geolocation_handler::{CefGeolocationCallback, CefGeolocationHandler};
-pub use interfaces::cef_geolocation_handler::{cef_geolocation_callback_t};
-pub use interfaces::cef_geolocation_handler::{cef_geolocation_handler_t};
-pub use interfaces::cef_jsdialog_handler::{CefJSDialogCallback, CefJSDialogHandler};
-pub use interfaces::cef_jsdialog_handler::{cef_jsdialog_callback_t, cef_jsdialog_handler_t};
-pub use interfaces::cef_keyboard_handler::{CefKeyboardHandler, cef_keyboard_handler_t};
-pub use interfaces::cef_life_span_handler::{CefLifeSpanHandler, cef_life_span_handler_t};
-pub use interfaces::cef_load_handler::{CefLoadHandler, cef_load_handler_t};
-pub use interfaces::cef_menu_model::{CefMenuModel, cef_menu_model_t};
-pub use interfaces::cef_print_handler::{CefPrintDialogCallback, CefPrintHandler};
-pub use interfaces::cef_print_handler::{CefPrintJobCallback, cef_print_dialog_callback_t};
-pub use interfaces::cef_print_handler::{cef_print_handler_t, cef_print_job_callback_t};
-pub use interfaces::cef_print_settings::{CefPrintSettings, cef_print_settings_t};
-pub use interfaces::cef_process_message::{CefProcessMessage, cef_process_message_t};
-pub use interfaces::cef_render_handler::{CefRenderHandler, cef_render_handler_t};
-pub use interfaces::cef_render_process_handler::{CefRenderProcessHandler};
-pub use interfaces::cef_render_process_handler::{cef_render_process_handler_t};
-pub use interfaces::cef_request::{CefPostData, CefPostDataElement, CefRequest};
-pub use interfaces::cef_request::{cef_post_data_element_t, cef_post_data_t, cef_request_t};
-pub use interfaces::cef_request_context::{CefRequestContext, cef_request_context_t};
-pub use interfaces::cef_request_context_handler::{CefRequestContextHandler};
-pub use interfaces::cef_request_context_handler::{cef_request_context_handler_t};
-pub use interfaces::cef_request_handler::{CefAllowCertificateErrorCallback, CefQuotaCallback};
-pub use interfaces::cef_request_handler::{CefRequestHandler};
-pub use interfaces::cef_request_handler::{cef_allow_certificate_error_callback_t};
-pub use interfaces::cef_request_handler::{cef_quota_callback_t, cef_request_handler_t};
-pub use interfaces::cef_resource_bundle_handler::{CefResourceBundleHandler};
-pub use interfaces::cef_resource_bundle_handler::{cef_resource_bundle_handler_t};
-pub use interfaces::cef_resource_handler::{CefResourceHandler, cef_resource_handler_t};
-pub use interfaces::cef_response::{CefResponse, cef_response_t};
-pub use interfaces::cef_scheme::{CefSchemeHandlerFactory, CefSchemeRegistrar};
-pub use interfaces::cef_scheme::{cef_scheme_handler_factory_t, cef_scheme_registrar_t};
-pub use interfaces::cef_stream::{CefReadHandler, CefStreamReader, CefStreamWriter};
-pub use interfaces::cef_stream::{CefWriteHandler, cef_read_handler_t, cef_stream_reader_t};
-pub use interfaces::cef_stream::{cef_stream_writer_t, cef_write_handler_t};
-pub use interfaces::cef_string_visitor::{CefStringVisitor, cef_string_visitor_t};
-pub use interfaces::cef_task::{CefTask, CefTaskRunner, cef_task_runner_t, cef_task_t};
-pub use interfaces::cef_trace::{CefEndTracingCallback, cef_end_tracing_callback_t};
-pub use interfaces::cef_urlrequest::{CefURLRequest, CefURLRequestClient, cef_urlrequest_client_t};
-pub use interfaces::cef_urlrequest::{cef_urlrequest_t};
-pub use interfaces::cef_v8::{CefV8Accessor, CefV8Context, CefV8Exception, CefV8Handler};
-pub use interfaces::cef_v8::{CefV8StackFrame, CefV8StackTrace, CefV8Value, cef_v8accessor_t};
-pub use interfaces::cef_v8::{cef_v8context_t, cef_v8exception_t, cef_v8handler_t};
-pub use interfaces::cef_v8::{cef_v8stack_frame_t, cef_v8stack_trace_t, cef_v8value_t};
-pub use interfaces::cef_values::{CefBinaryValue, CefDictionaryValue, CefListValue};
-pub use interfaces::cef_values::{cef_binary_value_t, cef_dictionary_value_t, cef_list_value_t};
-pub use interfaces::cef_web_plugin::{CefWebPluginInfo, CefWebPluginInfoVisitor};
-pub use interfaces::cef_web_plugin::{CefWebPluginUnstableCallback, cef_web_plugin_info_t};
-pub use interfaces::cef_web_plugin::{cef_web_plugin_info_visitor_t};
-pub use interfaces::cef_web_plugin::{cef_web_plugin_unstable_callback_t};
-pub use interfaces::cef_xml_reader::{CefXmlReader, cef_xml_reader_t};
-pub use interfaces::cef_zip_reader::{CefZipReader, cef_zip_reader_t};
-pub use types::{CefBase, CefBrowserSettings, CefCookie, CefGeoposition, CefKeyEvent};
-pub use types::{CefMouseEvent, CefPopupFeatures, CefProcessId, CefScreenInfo};
-pub use types::{CefValueType, CefWindowInfo, cef_base_t};
-pub use types::{cef_browser_settings_t, cef_cookie_t, cef_geoposition_t, cef_key_event_t};
-pub use types::{cef_mouse_event_t, cef_point_t, cef_popup_features_t};
-pub use types::{cef_process_id_t, cef_screen_info_t, cef_string_map_t};
-pub use types::{cef_time_t, cef_value_type_t, cef_window_info_t};
 
 pub mod cef_app;
 pub mod cef_auth_callback;
-pub mod cef_browser;
 pub mod cef_browser_process_handler;
+pub mod cef_browser;
 pub mod cef_callback;
 pub mod cef_client;
 pub mod cef_command_line;
@@ -112,28 +77,35 @@ pub mod cef_download_handler;
 pub mod cef_download_item;
 pub mod cef_drag_data;
 pub mod cef_drag_handler;
+pub mod cef_find_handler;
 pub mod cef_focus_handler;
 pub mod cef_frame;
-pub mod cef_geolocation;
 pub mod cef_geolocation_handler;
+pub mod cef_geolocation;
 pub mod cef_jsdialog_handler;
 pub mod cef_keyboard_handler;
 pub mod cef_life_span_handler;
 pub mod cef_load_handler;
 pub mod cef_menu_model;
+pub mod cef_navigation_entry;
+pub mod cef_origin_whitelist;
+pub mod cef_parser;
+pub mod cef_path_util;
 pub mod cef_print_handler;
 pub mod cef_print_settings;
 pub mod cef_process_message;
+pub mod cef_process_util;
 pub mod cef_render_handler;
 pub mod cef_render_process_handler;
-pub mod cef_request;
-pub mod cef_request_context;
 pub mod cef_request_context_handler;
+pub mod cef_request_context;
 pub mod cef_request_handler;
+pub mod cef_request;
 pub mod cef_resource_bundle_handler;
 pub mod cef_resource_handler;
 pub mod cef_response;
 pub mod cef_scheme;
+pub mod cef_ssl_info;
 pub mod cef_stream;
 pub mod cef_string_visitor;
 pub mod cef_task;
@@ -144,5 +116,3 @@ pub mod cef_values;
 pub mod cef_web_plugin;
 pub mod cef_xml_reader;
 pub mod cef_zip_reader;
-
-
diff --git a/servo/ports/cef/lib.rs b/servo/ports/cef/lib.rs
index 2f6718a1deab..ae9209022efd 100644
--- a/servo/ports/cef/lib.rs
+++ b/servo/ports/cef/lib.rs
@@ -13,7 +13,7 @@
 #![feature(collections)]
 #![feature(negate_unsigned)]
 #![feature(unicode)]
-
+#![feature(unsafe_no_drop_flag, filling_drop)]
 #![allow(non_camel_case_types)]
 
 #![plugin(plugins)]
diff --git a/servo/ports/cef/macros.rs b/servo/ports/cef/macros.rs
index 605b92da6728..f498769e6c94 100644
--- a/servo/ports/cef/macros.rs
+++ b/servo/ports/cef/macros.rs
@@ -66,7 +66,7 @@ macro_rules! full_cef_class_impl(
                     // Calculate the offset of the reference count. This is the size of the
                     // structure.
                     let null: *const $c_interface_name = ::std::ptr::null();
-                    let offset: *const usize = &(*null).ref_count;
+                    let offset: *const u32 = &(*null).ref_count;
                     let size = (offset as ::libc::size_t) - (null as ::libc::size_t);
                     $interface_name::from_c_object_addref(
                         ::eutil::create_cef_object::<$c_interface_name,$class_name>(size))
diff --git a/servo/ports/cef/regen_interface_mod_rs.sh b/servo/ports/cef/regen_interface_mod_rs.sh
new file mode 100755
index 000000000000..665a50957e04
--- /dev/null
+++ b/servo/ports/cef/regen_interface_mod_rs.sh
@@ -0,0 +1,45 @@
+#!/bin/zsh
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+setopt extended_glob
+echo -e $(cat << END_MPL
+/* This Source Code Form is subject to the terms of the Mozilla Public\n
+ * License, v. 2.0. If a copy of the MPL was not distributed with this\n
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */\n
+END_MPL) >>| interfaces_mod.rs
+
+# loop all files in interfaces dir
+for x in $(print interfaces/*.rs~interfaces/mod.rs)
+do
+    # open the use statement
+    echo -n "pub use interfaces::$(basename $x .rs)::{" >>| interfaces_mod.rs
+    # append all pub struct names which do not begin with '_'
+    grep -E '^pub struct [^_]' $x|sed 's/.*struct \(.*\) .*/\1/'|tr '\n' ',' >>| interfaces_mod.rs
+    # append all pub types
+    grep -E '^pub type ' $x|sed 's/pub type \([^ ]*\) .*/\1/'|tr '\n' ',' >>| interfaces_mod.rs
+    # close the use statement
+    echo '};' >>| interfaces_mod.rs
+done
+# open use statement for manually-generated types.rs
+echo -n "pub use types::{" >>| interfaces_mod.rs
+# append all pub types
+grep -E '^pub type ' types.rs|sed 's/pub type \([^ ]*\) .*/\1/'|uniq|tr '\n' ',' >>| interfaces_mod.rs
+# append all pub enums
+grep -E '^pub enum ' types.rs|sed 's/pub enum \([^ ]*\) .*/\1/'|uniq|tr '\n' ',' >>| interfaces_mod.rs
+# close use statement
+echo '};' >>| interfaces_mod.rs
+# append all pub structs beginning with "Cef" to alias them from types:: -> interfaces::
+# some generated code from cef uses interfaces:: for types that it does not generate
+grep -E '^pub struct Cef' types.rs|sed 's/pub struct \([^ ]*\) .*/pub use types::\1 as \1;/'|uniq >>| interfaces_mod.rs
+# newline separators
+echo -e '\n\n' >>| interfaces_mod.rs
+# loop all files in interfaces dir again
+for x in $(print interfaces/*.rs~interfaces/mod.rs)
+do
+    # add mod statements for all interfaces
+    echo "pub mod $(basename $x .rs);" >>| interfaces_mod.rs
+done
diff --git a/servo/ports/cef/request_context.rs b/servo/ports/cef/request_context.rs
index d5b01f08b08c..2187e32b8f6f 100644
--- a/servo/ports/cef/request_context.rs
+++ b/servo/ports/cef/request_context.rs
@@ -2,11 +2,15 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use interfaces::{cef_request_context_handler_t, cef_request_context_t};
+use interfaces::{cef_request_context_handler_t, cef_request_context_t, cef_request_context_settings_t};
 
 cef_stub_static_method_impls! {
     fn cef_request_context_get_global_context() -> *mut cef_request_context_t
-    fn cef_request_context_create_context(_handler: *mut cef_request_context_handler_t)
+    fn cef_request_context_create_context(_settings: *const cef_request_context_settings_t,
+                                          _handler: *mut cef_request_context_handler_t)
+                                          -> *mut cef_request_context_t
+    fn cef_request_context_create_context_shared(_other: *mut cef_request_context_t,
+                                                 _handler: *mut cef_request_context_handler_t)
                                           -> *mut cef_request_context_t
 }
 
diff --git a/servo/ports/cef/types.rs b/servo/ports/cef/types.rs
index 5c0f59791cff..4369930b105f 100644
--- a/servo/ports/cef/types.rs
+++ b/servo/ports/cef/types.rs
@@ -17,28 +17,6 @@ pub enum cef_string_list_t {}
 pub enum cef_text_input_context_t {}
 pub enum cef_event_handle_t {}
 
-//these all need to be done...
-pub enum cef_binary_value_t {}
-pub enum cef_dictionary_value_t {}
-pub enum cef_request_t {}
-pub enum cef_response_t {}
-pub enum cef_urlrequest_client_t {}
-pub enum cef_domnode_t {}
-pub enum cef_load_handler_t {}
-pub enum cef_browser_settings_t {}
-pub enum cef_v8context_t {}
-pub enum cef_v8exception_t {}
-pub enum cef_v8stack_trace_t {}
-pub enum cef_context_menu_handler_t {}
-pub enum cef_dialog_handler_t {}
-pub enum cef_download_handler_t {}
-pub enum cef_drag_handler_t {}
-pub enum cef_focus_handler_t {}
-pub enum cef_geolocation_handler_t {}
-pub enum cef_jsdialog_handler_t {}
-pub enum cef_keyboard_handler_t {}
-pub enum cef_render_handler_t {}
-pub enum cef_request_handler_t {}
 #[cfg(target_os="linux")]
 pub type cef_window_handle_t = c_ulong;
 #[cfg(target_os="macos")]
@@ -52,20 +30,6 @@ pub type cef_cursor_handle_t = *mut c_void; //NSCursor*
 //#[cfg(target_os="win")]
 //pub enum cef_cursor_handle_t {} //HCURSOR
 
-pub enum cef_request_val {}
-pub type cef_request = *mut cef_request_val;
-pub enum cef_navigation_type_val {}
-pub type cef_navigation_type = *mut cef_navigation_type_val;
-pub enum cef_screen_info_t {}
-pub type cef_v8context = *mut cef_v8context_t;
-pub enum cef_v8exception_val {}
-pub type cef_v8exception = *mut cef_v8exception_val;
-pub enum cef_v8stack_trace_val {}
-pub type cef_v8stack_trace = *mut cef_v8stack_trace_val;
-
-pub type CefBrowserSettings = cef_browser_settings_t;
-pub type CefScreenInfo = cef_screen_info_t;
-
 pub type cef_string_t = cef_string_utf16; //FIXME: this is #defined...
 pub type cef_string_userfree_t = *mut cef_string_t; //FIXME: this is #defined...
 
@@ -101,6 +65,25 @@ pub struct cef_main_args {
 
 pub type cef_color_t = c_uint;
 
+///
+// Represents the state of a setting.
+///
+pub enum cef_state_t {
+    ///
+    // Use the default state for the setting.
+    ///
+    STATE_DEFAULT = 0,
+
+    ///
+    // Enable or allow the setting.
+    ///
+    STATE_ENABLED,
+
+    ///
+    // Disable or disallow the setting.
+    ///
+    STATE_DISABLED,
+}
 //
 // Existing thread IDs.
 //
@@ -1570,3 +1553,415 @@ pub enum cef_xml_encoding_type_t {
     XML_ENCODING_ASCII,
 }
 
+///
+// The manner in which a link click should be opened.
+///
+pub enum cef_window_open_disposition_t {
+    WOD_UNKNOWN = 0,
+    WOD_SUPPRESS_OPEN,
+    WOD_CURRENT_TAB,
+    WOD_SINGLETON_TAB,
+    WOD_NEW_FOREGROUND_TAB,
+    WOD_NEW_BACKGROUND_TAB,
+    WOD_NEW_POPUP,
+    WOD_NEW_WINDOW,
+    WOD_SAVE_TO_DISK,
+    WOD_OFF_THE_RECORD,
+    WOD_IGNORE_ACTION
+}
+
+
+///
+// Cursor type values.
+///
+pub enum cef_cursor_type_t {
+    CT_POINTER = 0,
+    CT_CROSS,
+    CT_HAND,
+    CT_IBEAM,
+    CT_WAIT,
+    CT_HELP,
+    CT_EASTRESIZE,
+    CT_NORTHRESIZE,
+    CT_NORTHEASTRESIZE,
+    CT_NORTHWESTRESIZE,
+    CT_SOUTHRESIZE,
+    CT_SOUTHEASTRESIZE,
+    CT_SOUTHWESTRESIZE,
+    CT_WESTRESIZE,
+    CT_NORTHSOUTHRESIZE,
+    CT_EASTWESTRESIZE,
+    CT_NORTHEASTSOUTHWESTRESIZE,
+    CT_NORTHWESTSOUTHEASTRESIZE,
+    CT_COLUMNRESIZE,
+    CT_ROWRESIZE,
+    CT_MIDDLEPANNING,
+    CT_EASTPANNING,
+    CT_NORTHPANNING,
+    CT_NORTHEASTPANNING,
+    CT_NORTHWESTPANNING,
+    CT_SOUTHPANNING,
+    CT_SOUTHEASTPANNING,
+    CT_SOUTHWESTPANNING,
+    CT_WESTPANNING,
+    CT_MOVE,
+    CT_VERTICALTEXT,
+    CT_CELL,
+    CT_CONTEXTMENU,
+    CT_ALIAS,
+    CT_PROGRESS,
+    CT_NODROP,
+    CT_COPY,
+    CT_NONE,
+    CT_NOTALLOWED,
+    CT_ZOOMIN,
+    CT_ZOOMOUT,
+    CT_GRAB,
+    CT_GRABBING,
+    CT_CUSTOM,
+}
+
+///
+// Screen information used when window rendering is disabled. This structure is
+// passed as a parameter to CefRenderHandler::GetScreenInfo and should be filled
+// in by the client.
+///
+pub struct _cef_screen_info {
+  ///
+  // Device scale factor. Specifies the ratio between physical and logical
+  // pixels.
+  ///
+  pub device_scale_factor: f32,
+
+  ///
+  // The screen depth in bits per pixel.
+  ///
+  pub depth: i32,
+
+  ///
+  // The bits per color component. This assumes that the colors are balanced
+  // equally.
+  ///
+  pub depth_per_component: i32,
+
+  ///
+  // This can be true for black and white printers.
+  ///
+  pub is_monochrome: i32,
+
+  ///
+  // This is set from the rcMonitor member of MONITORINFOEX, to whit:
+  //   "A RECT structure that specifies the display monitor rectangle,
+  //   expressed in virtual-screen coordinates. Note that if the monitor
+  //   is not the primary display monitor, some of the rectangle's
+  //   coordinates may be negative values."
+  //
+  // The |rect| and |available_rect| properties are used to determine the
+  // available surface for rendering popup views.
+  ///
+  pub rect: cef_rect_t,
+
+  ///
+  // This is set from the rcWork member of MONITORINFOEX, to whit:
+  //   "A RECT structure that specifies the work area rectangle of the
+  //   display monitor that can be used by applications, expressed in
+  //   virtual-screen coordinates. Windows uses this rectangle to
+  //   maximize an application on the monitor. The rest of the area in
+  //   rcMonitor contains system windows such as the task bar and side
+  //   bars. Note that if the monitor is not the primary display monitor,
+  //   some of the rectangle's coordinates may be negative values".
+  //
+  // The |rect| and |available_rect| properties are used to determine the
+  // available surface for rendering popup views.
+  ///
+  pub available_rect: cef_rect_t,
+}
+
+pub type cef_screen_info_t = _cef_screen_info;
+pub type CefScreenInfo = cef_screen_info_t;
+
+///
+// Browser initialization settings. Specify NULL or 0 to get the recommended
+// default values. The consequences of using custom values may not be well
+// tested. Many of these and other settings can also configured using command-
+// line switches.
+///
+pub struct _cef_browser_settings {
+    ///
+    // Size of this structure.
+    ///
+    pub size: u64,
+
+    ///
+    // The maximum rate in frames per second (fps) that CefRenderHandler::OnPaint
+    // will be called for a windowless browser. The actual fps may be lower if
+    // the browser cannot generate frames at the requested rate. The minimum
+    // value is 1 and the maximum value is 60 (default 30).
+    ///
+    pub windowless_frame_rate: i32,
+
+    // The below values map to WebPreferences settings.
+
+    ///
+    // Font settings.
+    ///
+    pub standard_font_family: cef_string_t,
+    pub fixed_font_family: cef_string_t,
+    pub serif_font_family: cef_string_t,
+    pub sans_serif_font_family: cef_string_t,
+    pub cursive_font_family: cef_string_t,
+    pub fantasy_font_family: cef_string_t,
+    pub default_font_size: i32,
+    pub default_fixed_font_size: i32,
+    pub minimum_font_size: i32,
+    pub minimum_logical_font_size: i32,
+
+    ///
+    // Default encoding for Web content. If empty "ISO-8859-1" will be used. Also
+    // configurable using the "default-encoding" command-line switch.
+    ///
+    pub default_encoding: cef_string_t,
+
+    ///
+    // Controls the loading of fonts from remote sources. Also configurable using
+    // the "disable-remote-fonts" command-line switch.
+    ///
+    pub remote_fonts: cef_state_t,
+
+    ///
+    // Controls whether JavaScript can be executed. Also configurable using the
+    // "disable-javascript" command-line switch.
+    ///
+    pub javascript: cef_state_t,
+
+    ///
+    // Controls whether JavaScript can be used for opening windows. Also
+    // configurable using the "disable-javascript-open-windows" command-line
+    // switch.
+    ///
+    pub javascript_open_windows: cef_state_t,
+
+    ///
+    // Controls whether JavaScript can be used to close windows that were not
+    // opened via JavaScript. JavaScript can still be used to close windows that
+    // were opened via JavaScript or that have no back/forward history. Also
+    // configurable using the "disable-javascript-close-windows" command-line
+    // switch.
+    ///
+    pub javascript_close_windows: cef_state_t,
+
+    ///
+    // Controls whether JavaScript can access the clipboard. Also configurable
+    // using the "disable-javascript-access-clipboard" command-line switch.
+    ///
+    pub javascript_access_clipboard: cef_state_t,
+
+    ///
+    // Controls whether DOM pasting is supported in the editor via
+    // execCommand("paste"). The |javascript_access_clipboard| setting must also
+    // be enabled. Also configurable using the "disable-javascript-dom-paste"
+    // command-line switch.
+    ///
+    pub javascript_dom_paste: cef_state_t,
+
+    ///
+    // Controls whether the caret position will be drawn. Also configurable using
+    // the "enable-caret-browsing" command-line switch.
+    ///
+    pub caret_browsing: cef_state_t,
+
+    ///
+    // Controls whether the Java plugin will be loaded. Also configurable using
+    // the "disable-java" command-line switch.
+    ///
+    pub java: cef_state_t,
+
+    ///
+    // Controls whether any plugins will be loaded. Also configurable using the
+    // "disable-plugins" command-line switch.
+    ///
+    pub plugins: cef_state_t,
+
+    ///
+    // Controls whether file URLs will have access to all URLs. Also configurable
+    // using the "allow-universal-access-from-files" command-line switch.
+    ///
+    pub universal_access_from_file_urls: cef_state_t,
+
+    ///
+    // Controls whether file URLs will have access to other file URLs. Also
+    // configurable using the "allow-access-from-files" command-line switch.
+    ///
+    pub file_access_from_file_urls: cef_state_t,
+
+    ///
+    // Controls whether web security restrictions (same-origin policy) will be
+    // enforced. Disabling this setting is not recommend as it will allow risky
+    // security behavior such as cross-site scripting (XSS). Also configurable
+    // using the "disable-web-security" command-line switch.
+    ///
+    pub web_security: cef_state_t,
+
+    ///
+    // Controls whether image URLs will be loaded from the network. A cached image
+    // will still be rendered if requested. Also configurable using the
+    // "disable-image-loading" command-line switch.
+    ///
+    pub image_loading: cef_state_t,
+
+    ///
+    // Controls whether standalone images will be shrunk to fit the page. Also
+    // configurable using the "image-shrink-standalone-to-fit" command-line
+    // switch.
+    ///
+    pub image_shrink_standalone_to_fit: cef_state_t,
+
+    ///
+    // Controls whether text areas can be resized. Also configurable using the
+    // "disable-text-area-resize" command-line switch.
+    ///
+    pub text_area_resize: cef_state_t,
+
+    ///
+    // Controls whether the tab key can advance focus to links. Also configurable
+    // using the "disable-tab-to-links" command-line switch.
+    ///
+    pub tab_to_links: cef_state_t,
+
+    ///
+    // Controls whether local storage can be used. Also configurable using the
+    // "disable-local-storage" command-line switch.
+    ///
+    pub local_storage: cef_state_t,
+
+    ///
+    // Controls whether databases can be used. Also configurable using the
+    // "disable-databases" command-line switch.
+    ///
+    pub databases: cef_state_t,
+
+    ///
+    // Controls whether the application cache can be used. Also configurable using
+    // the "disable-application-cache" command-line switch.
+    ///
+    pub application_cache: cef_state_t,
+
+    ///
+    // Controls whether WebGL can be used. Note that WebGL requires hardware
+    // support and may not work on all systems even when enabled. Also
+    // configurable using the "disable-webgl" command-line switch.
+    ///
+    pub webgl: cef_state_t,
+
+    ///
+    // Opaque background color used for the browser before a document is loaded
+    // and when no document color is specified. By default the background color
+    // will be the same as CefSettings.background_color. Only the RGB compontents
+    // of the specified value will be used. The alpha component must greater than
+    // 0 to enable use of the background color but will be otherwise ignored.
+    ///
+    pub background_color: cef_color_t,
+
+    ///
+    // Comma delimited ordered list of language codes without any whitespace that
+    // will be used in the "Accept-Language" HTTP header. May be set globally
+    // using the CefBrowserSettings.accept_language_list value. If both values are
+    // empty then "en-US,en" will be used.
+    ///
+    pub accept_language_list: cef_string_t,
+}
+
+pub type cef_browser_settings_t = _cef_browser_settings;
+pub type CefBrowserSettings = cef_browser_settings_t;
+
+
+///
+// Structure representing cursor information. |buffer| will be
+// |size.width|*|size.height|*4 bytes in size and represents a BGRA image with
+// an upper-left origin.
+///
+pub struct _cef_cursor_info {
+    pub hotspot: cef_point_t,
+    pub image_scale_factor: f32,
+    pub buffer: *mut isize,
+    pub size: cef_size_t,
+}
+
+pub type cef_cursor_info_t = _cef_cursor_info;
+pub type CefCursorInfo = cef_cursor_info_t;
+
+///
+// Return value types.
+///
+pub enum cef_return_value_t {
+    ///
+    // Cancel immediately.
+    ///
+    RV_CANCEL = 0,
+
+    ///
+    // Continue immediately.
+    ///
+    RV_CONTINUE,
+
+    ///
+    // Continue asynchronously (usually via a callback).
+    ///
+    RV_CONTINUE_ASYNC,
+}
+
+
+
+///
+// Request context initialization settings. Specify NULL or 0 to get the
+// recommended default values.
+///
+pub struct _cef_request_context_settings {
+  ///
+  // Size of this structure.
+  ///
+  pub size: size_t,
+
+  ///
+  // The location where cache data will be stored on disk. If empty then
+  // browsers will be created in "incognito mode" where in-memory caches are
+  // used for storage and no data is persisted to disk. HTML5 databases such as
+  // localStorage will only persist across sessions if a cache path is
+  // specified. To share the global browser cache and related configuration set
+  // this value to match the CefSettings.cache_path value.
+  ///
+  pub cache_path: cef_string_t,
+
+  ///
+  // To persist session cookies (cookies without an expiry date or validity
+  // interval) by default when using the global cookie manager set this value to
+  // true. Session cookies are generally intended to be transient and most Web
+  // browsers do not persist them. Can be set globally using the
+  // CefSettings.persist_session_cookies value. This value will be ignored if
+  // |cache_path| is empty or if it matches the CefSettings.cache_path value.
+  ///
+  pub persist_session_cookies: i32,
+
+  ///
+  // Set to true (1) to ignore errors related to invalid SSL certificates.
+  // Enabling this setting can lead to potential security vulnerabilities like
+  // "man in the middle" attacks. Applications that load content from the
+  // internet should not enable this setting. Can be set globally using the
+  // CefSettings.ignore_certificate_errors value. This value will be ignored if
+  // |cache_path| matches the CefSettings.cache_path value.
+  ///
+  pub ignore_certificate_errors: i32,
+
+  ///
+  // Comma delimited ordered list of language codes without any whitespace that
+  // will be used in the "Accept-Language" HTTP header. Can be set globally
+  // using the CefSettings.accept_language_list value or overridden on a per-
+  // browser basis using the CefBrowserSettings.accept_language_list value. If
+  // all values are empty then "en-US,en" will be used. This value will be
+  // ignored if |cache_path| matches the CefSettings.cache_path value.
+  ///
+  pub accept_language_list: cef_string_t,
+}
+
+pub type cef_request_context_settings_t = _cef_request_context_settings;
+pub type CefRequestContextSettings = cef_request_context_settings_t;
diff --git a/servo/ports/cef/urlrequest.rs b/servo/ports/cef/urlrequest.rs
index 77938e858b67..99d8cb53eee3 100644
--- a/servo/ports/cef/urlrequest.rs
+++ b/servo/ports/cef/urlrequest.rs
@@ -2,11 +2,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use interfaces::{cef_request_t, cef_urlrequest_client_t, cef_urlrequest_t};
+use interfaces::{cef_request_t, cef_request_context_t, cef_urlrequest_client_t, cef_urlrequest_t};
 
 #[no_mangle]
 pub extern "C" fn cef_urlrequest_create(_request: *mut cef_request_t,
-                                        _client: *mut cef_urlrequest_client_t)
+                                        _client: *mut cef_urlrequest_client_t,
+                                        _context: *mut cef_request_context_t)
                                         -> *mut cef_urlrequest_t {
     0 as *mut cef_urlrequest_t
 }
diff --git a/servo/ports/cef/values.rs b/servo/ports/cef/values.rs
index 29ad0b6dfdc2..b7779699db02 100644
--- a/servo/ports/cef/values.rs
+++ b/servo/ports/cef/values.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use interfaces::{cef_binary_value_t, cef_dictionary_value_t, cef_list_value_t};
+use interfaces::{cef_binary_value_t, cef_dictionary_value_t, cef_list_value_t, cef_value_t};
 
 use libc;
 
@@ -10,5 +10,6 @@ cef_stub_static_method_impls! {
     fn cef_binary_value_create(_data: *const (), _size: libc::size_t) -> *mut cef_binary_value_t
     fn cef_dictionary_value_create() -> *mut cef_dictionary_value_t
     fn cef_list_value_create() -> *mut cef_list_value_t
+    fn cef_value_create() -> *mut cef_value_t
 }
 
diff --git a/servo/ports/cef/window.rs b/servo/ports/cef/window.rs
index 90740c546222..1cc8051697d7 100644
--- a/servo/ports/cef/window.rs
+++ b/servo/ports/cef/window.rs
@@ -11,7 +11,7 @@ use eutil::Downcast;
 use interfaces::CefBrowser;
 use render_handler::CefRenderHandlerExtensions;
 use rustc_unicode::str::Utf16Encoder;
-use types::{cef_cursor_handle_t, cef_rect_t};
+use types::{cef_cursor_handle_t, cef_cursor_type_t, cef_rect_t};
 
 use compositing::compositor_task::{self, CompositorProxy, CompositorReceiver};
 use compositing::windowing::{WindowEvent, WindowMethods};
@@ -87,6 +87,33 @@ impl Window {
         WindowEvent::Idle
     }
 
+    fn cursor_type_for_cursor(&self, cursor: Cursor) -> cef_cursor_type_t {
+        match cursor {
+            Cursor::NoCursor => return cef_cursor_type_t::CT_NONE,
+            Cursor::ContextMenuCursor => return cef_cursor_type_t::CT_CONTEXTMENU,
+            Cursor::GrabbingCursor => return cef_cursor_type_t::CT_GRABBING,
+            Cursor::CrosshairCursor => return cef_cursor_type_t::CT_CROSS,
+            Cursor::CopyCursor => return cef_cursor_type_t::CT_COPY,
+            Cursor::AliasCursor => return cef_cursor_type_t::CT_ALIAS,
+            Cursor::TextCursor => return cef_cursor_type_t::CT_IBEAM,
+            Cursor::GrabCursor | Cursor::AllScrollCursor =>
+                return cef_cursor_type_t::CT_GRAB,
+            Cursor::NoDropCursor => return cef_cursor_type_t::CT_NODROP,
+            Cursor::NotAllowedCursor => return cef_cursor_type_t::CT_NOTALLOWED,
+            Cursor::PointerCursor => return cef_cursor_type_t::CT_POINTER,
+            Cursor::SResizeCursor => return cef_cursor_type_t::CT_SOUTHRESIZE,
+            Cursor::WResizeCursor => return cef_cursor_type_t::CT_WESTRESIZE,
+            Cursor::EwResizeCursor => return cef_cursor_type_t::CT_EASTWESTRESIZE,
+            Cursor::ColResizeCursor => return cef_cursor_type_t::CT_COLUMNRESIZE,
+            Cursor::EResizeCursor => return cef_cursor_type_t::CT_EASTRESIZE,
+            Cursor::NResizeCursor => return cef_cursor_type_t::CT_NORTHRESIZE,
+            Cursor::NsResizeCursor => return cef_cursor_type_t::CT_NORTHSOUTHRESIZE,
+            Cursor::RowResizeCursor => return cef_cursor_type_t::CT_ROWRESIZE,
+            Cursor::VerticalTextCursor => return cef_cursor_type_t::CT_VERTICALTEXT,
+            _ => return cef_cursor_type_t::CT_POINTER,
+        }
+    }
+
     /// Returns the Cocoa cursor for a CSS cursor. These match Firefox, except where Firefox
     /// bundles custom resources (which we don't yet do).
     #[cfg(target_os="macos")]
@@ -307,15 +334,18 @@ impl WindowMethods for Window {
     }
 
     fn set_cursor(&self, cursor: Cursor) {
+        use types::{CefCursorInfo,cef_point_t,cef_size_t};
         let browser = self.cef_browser.borrow();
         match *browser {
             None => {}
             Some(ref browser) => {
                 let cursor_handle = self.cursor_handle_for_cursor(cursor);
+                let info = CefCursorInfo { hotspot: cef_point_t {x: 0, y: 0}, image_scale_factor: 0.0, buffer: 0 as *mut isize, size: cef_size_t { width: 0, height: 0 } };
                 browser.get_host()
                        .get_client()
                        .get_render_handler()
-                       .on_cursor_change(browser.clone(), cursor_handle)
+                       .on_cursor_change(browser.clone(), cursor_handle,
+                         self.cursor_type_for_cursor(cursor), &info)
             }
         }
     }
diff --git a/servo/ports/cef/wrappers.rs b/servo/ports/cef/wrappers.rs
index 0ac8b5f668be..edeb664e2e5d 100644
--- a/servo/ports/cef/wrappers.rs
+++ b/servo/ports/cef/wrappers.rs
@@ -4,32 +4,34 @@
 
 use interfaces::{cef_drag_data_t, cef_post_data_element_t, cef_v8value_t, CefPostDataElement};
 use interfaces::{CefV8Value};
+use interfaces::{cef_download_handler_t, cef_drag_handler_t, cef_context_menu_handler_t};
+use interfaces::{cef_dialog_handler_t, cef_focus_handler_t};
+use interfaces::{cef_load_handler_t, cef_request_handler_t};
+use interfaces::{cef_geolocation_handler_t, cef_jsdialog_handler_t, cef_keyboard_handler_t};
 use rustc_unicode::str::Utf16Encoder;
-use types::{cef_base_t, cef_browser_settings_t, cef_color_model_t};
-use types::{cef_context_menu_edit_state_flags_t, cef_context_menu_handler_t};
+use types::{cef_base_t, cef_browser_settings_t, CefBrowserSettings, cef_color_model_t};
+use types::{cef_context_menu_edit_state_flags_t};
 use types::{cef_context_menu_media_state_flags_t};
-use types::{cef_context_menu_media_type_t, cef_context_menu_type_flags_t, cef_cookie_t};
-use types::{cef_dialog_handler_t};
+use types::{cef_context_menu_media_type_t, cef_context_menu_type_flags_t, cef_cookie_t, cef_cursor_info_t, CefCursorInfo, cef_cursor_type_t};
 use types::{cef_dom_document_type_t, cef_dom_node_type_t};
-use types::{cef_download_handler_t, cef_drag_handler_t};
 use types::{cef_drag_operations_mask_t, cef_duplex_mode_t};
 use types::{cef_errorcode_t, cef_event_flags_t, cef_event_handle_t};
-use types::{cef_file_dialog_mode_t, cef_focus_handler_t, cef_focus_source_t};
-use types::{cef_geolocation_handler_t, cef_geoposition_t};
-use types::{cef_jsdialog_handler_t, cef_jsdialog_type_t};
-use types::{cef_key_event, cef_keyboard_handler_t};
-use types::{cef_load_handler_t, cef_menu_item_type_t, cef_mouse_button_type_t};
+use types::{cef_file_dialog_mode_t, cef_focus_source_t};
+use types::{cef_geoposition_t};
+use types::{cef_jsdialog_type_t};
+use types::{cef_key_event};
+use types::{cef_menu_item_type_t, cef_mouse_button_type_t};
 use types::{cef_mouse_event, cef_navigation_type_t};
 use types::{cef_page_range_t, cef_paint_element_type_t, cef_point_t, cef_postdataelement_type_t};
 use types::{cef_popup_features_t, cef_process_id_t};
-use types::{cef_rect_t, cef_request_handler_t};
-use types::{cef_resource_type_t};
-use types::{cef_screen_info_t, cef_size_t, cef_string_t, cef_string_userfree_t};
+use types::{cef_rect_t, cef_request_context_settings_t, CefRequestContextSettings};
+use types::{cef_resource_type_t, cef_return_value_t};
+use types::{cef_screen_info_t, CefScreenInfo, cef_size_t, cef_string_t, cef_string_userfree_t};
 use types::{cef_string_list_t, cef_string_map_t, cef_string_multimap_t, cef_string_utf16};
 use types::{cef_termination_status_t, cef_text_input_context_t, cef_thread_id_t};
 use types::{cef_time_t, cef_transition_type_t, cef_urlrequest_status_t};
 use types::{cef_v8_accesscontrol_t, cef_v8_propertyattribute_t, cef_value_type_t};
-use types::{cef_window_info_t, cef_xml_encoding_type_t, cef_xml_node_type_t};
+use types::{cef_window_info_t, cef_window_open_disposition_t, cef_xml_encoding_type_t, cef_xml_node_type_t};
 
 use libc::{self, c_char, c_int, c_ushort, c_void};
 use std::boxed;
@@ -99,6 +101,7 @@ cef_pointer_wrapper!(c_void);
 cef_pointer_wrapper!(cef_base_t);
 cef_pointer_wrapper!(cef_browser_settings_t);
 cef_pointer_wrapper!(cef_cookie_t);
+cef_pointer_wrapper!(cef_cursor_info_t);
 cef_pointer_wrapper!(cef_geoposition_t);
 cef_pointer_wrapper!(cef_key_event);
 cef_pointer_wrapper!(cef_mouse_event);
@@ -106,6 +109,7 @@ cef_pointer_wrapper!(cef_page_range_t);
 cef_pointer_wrapper!(cef_point_t);
 cef_pointer_wrapper!(cef_popup_features_t);
 cef_pointer_wrapper!(cef_rect_t);
+cef_pointer_wrapper!(cef_request_context_settings_t);
 cef_pointer_wrapper!(cef_screen_info_t);
 cef_pointer_wrapper!(cef_size_t);
 cef_pointer_wrapper!(cef_time_t);
@@ -133,11 +137,16 @@ cef_noop_wrapper!(*mut cef_request_handler_t);
 cef_noop_wrapper!(*mut cef_string_list_t);
 cef_noop_wrapper!(*mut cef_string_utf16);
 cef_noop_wrapper!(c_int);
+cef_noop_wrapper!(CefBrowserSettings);
+cef_noop_wrapper!(CefScreenInfo);
+cef_noop_wrapper!(CefRequestContextSettings);
+cef_noop_wrapper!(CefCursorInfo);
 cef_noop_wrapper!(cef_color_model_t);
 cef_noop_wrapper!(cef_context_menu_edit_state_flags_t);
 cef_noop_wrapper!(cef_context_menu_media_state_flags_t);
 cef_noop_wrapper!(cef_context_menu_media_type_t);
 cef_noop_wrapper!(cef_context_menu_type_flags_t);
+cef_noop_wrapper!(cef_cursor_type_t);
 cef_noop_wrapper!(cef_dom_document_type_t);
 cef_noop_wrapper!(cef_dom_node_type_t);
 cef_noop_wrapper!(cef_drag_operations_mask_t);
@@ -157,6 +166,7 @@ cef_noop_wrapper!(cef_paint_element_type_t);
 cef_noop_wrapper!(cef_postdataelement_type_t);
 cef_noop_wrapper!(cef_process_id_t);
 cef_noop_wrapper!(cef_resource_type_t);
+cef_noop_wrapper!(cef_return_value_t);
 cef_noop_wrapper!(cef_termination_status_t);
 cef_noop_wrapper!(cef_text_input_context_t);
 cef_noop_wrapper!(cef_thread_id_t);
@@ -166,6 +176,7 @@ cef_noop_wrapper!(cef_urlrequest_status_t);
 cef_noop_wrapper!(cef_v8_accesscontrol_t);
 cef_noop_wrapper!(cef_v8_propertyattribute_t);
 cef_noop_wrapper!(cef_value_type_t);
+cef_noop_wrapper!(cef_window_open_disposition_t);
 cef_noop_wrapper!(cef_xml_encoding_type_t);
 cef_noop_wrapper!(cef_xml_node_type_t);
 cef_noop_wrapper!(f64);