diff --git a/content/html/content/src/nsHTMLMediaElement.cpp b/content/html/content/src/nsHTMLMediaElement.cpp
index aa93eedbdfa..c0f4ac82b8c 100644
--- a/content/html/content/src/nsHTMLMediaElement.cpp
+++ b/content/html/content/src/nsHTMLMediaElement.cpp
@@ -259,6 +259,20 @@ NS_IMETHODIMP nsHTMLMediaElement::Load()
     mChannel = nsnull;
   }
 
+  PRInt16 shouldLoad = nsIContentPolicy::ACCEPT;
+  rv = NS_CheckContentLoadPolicy(nsIContentPolicy::TYPE_MEDIA,
+                                 uri,
+                                 NodePrincipal(),
+                                 this,
+                                 EmptyCString(), // mime type
+                                 nsnull, // extra
+                                 &shouldLoad,
+                                 nsContentUtils::GetContentPolicy(),
+                                 nsContentUtils::GetSecurityManager());
+  if (NS_FAILED(rv) || NS_CP_REJECTED(shouldLoad)) {
+    return NS_ERROR_CONTENT_BLOCKED;
+  }
+
   rv = NS_NewChannel(getter_AddRefs(mChannel),
                      uri,
                      nsnull,
diff --git a/editor/libeditor/base/tests/test_selection_move_commands.xul b/editor/libeditor/base/tests/test_selection_move_commands.xul
index a016240c325..fae1c310c0a 100644
--- a/editor/libeditor/base/tests/test_selection_move_commands.xul
+++ b/editor/libeditor/base/tests/test_selection_move_commands.xul
@@ -10,6 +10,17 @@
 <script class="testbody" type="application/javascript">
 <![CDATA[
 
+function runTest() {
+  var tests = execTests();
+  function execNext() {
+    try {
+      tests.next();
+      setTimeout(execNext, 0);
+    } catch (e) {}
+  }
+  execNext();
+}
+
 function execTests() {
   var e = document.getElementById("edit");
   var doc = e.contentDocument;
@@ -189,7 +200,7 @@ function execTests() {
 }
 
 SimpleTest.waitForExplicitFinish();
-addLoadEvent(execTests);
+addLoadEvent(runTest);
 ]]>
 </script>
 
diff --git a/editor/libeditor/html/nsHTMLEditRules.cpp b/editor/libeditor/html/nsHTMLEditRules.cpp
index 482b4f3905d..d71fbacafcd 100644
--- a/editor/libeditor/html/nsHTMLEditRules.cpp
+++ b/editor/libeditor/html/nsHTMLEditRules.cpp
@@ -1948,24 +1948,10 @@ nsHTMLEditRules::WillDeleteSelection(nsISelection *aSelection,
     if (NS_FAILED(res)) return res;
     if (*aCancel) return NS_OK;
 
-    res = mHTMLEditor->ExtendSelectionForDelete(aSelection, &aAction);
-    NS_ENSURE_SUCCESS(res, res);
-
     // We should delete nothing.
     if (aAction == nsIEditor::eNone)
       return NS_OK;
 
-    // ExtendSelectionForDelete() may have changed the selection, update it
-    res = mHTMLEditor->GetStartNodeAndOffset(aSelection, address_of(startNode), &startOffset);
-    if (NS_FAILED(res)) return res;
-    if (!startNode) return NS_ERROR_FAILURE;
-    
-    res = aSelection->GetIsCollapsed(&bCollapsed);
-    if (NS_FAILED(res)) return res;
-  }
-
-  if (bCollapsed)
-  {
     // what's in the direction we are deleting?
     nsWSRunObject wsObj(mHTMLEditor, startNode, startOffset);
     nsCOMPtr<nsIDOMNode> visNode;
@@ -2010,6 +1996,9 @@ nsHTMLEditRules::WillDeleteSelection(nsISelection *aSelection,
       }
       else
       {
+        res = mHTMLEditor->ExtendSelectionForDelete(aSelection, &aAction);
+        NS_ENSURE_SUCCESS(res, res);
+
         nsCOMPtr<nsIDOMRange> range;
         res = aSelection->GetRangeAt(0, getter_AddRefs(range));
         NS_ENSURE_SUCCESS(res, res);
@@ -2026,8 +2015,6 @@ nsHTMLEditRules::WillDeleteSelection(nsISelection *aSelection,
         NS_ASSERTION(container == visNode, "selection end not in visNode");
 #endif
 
-        res = range->GetStartOffset(&so);
-        NS_ENSURE_SUCCESS(res, res);
         res = range->GetEndOffset(&eo);
         NS_ENSURE_SUCCESS(res, res);
       }
diff --git a/layout/generic/test/Makefile.in b/layout/generic/test/Makefile.in
index 220baaeb873..8abda98b2ed 100644
--- a/layout/generic/test/Makefile.in
+++ b/layout/generic/test/Makefile.in
@@ -68,7 +68,7 @@ _TEST_FILES = 	test_bug288789.html \
 		test_bug469613.xul \
 		test_character_movement.html \
 		test_word_movement.html \
-		test_backspace_delete.xul \
+		test_backspace_delete.html \
 		$(NULL)
 
 libs:: $(_TEST_FILES)
diff --git a/layout/generic/test/test_backspace_delete.xul b/layout/generic/test/test_backspace_delete.html
similarity index 50%
rename from layout/generic/test/test_backspace_delete.xul
rename to layout/generic/test/test_backspace_delete.html
index e9cef09d9f7..ef2a9c3d8c3 100644
--- a/layout/generic/test/test_backspace_delete.xul
+++ b/layout/generic/test/test_backspace_delete.html
@@ -1,63 +1,62 @@
-<?xml version="1.0"?>
-<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
-<?xml-stylesheet href="/tests/SimpleTest/test.css" type="text/css"?>
-<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
-        xmlns:html="http://www.w3.org/1999/xhtml"
-        title="Test BackSpace/Delete Keys">
-  <script type="application/javascript" src="/MochiKit/packed.js"></script>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test BackSpace/Delete Keys</title>
+  <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: block">
+<div contentEditable id="editor"></div>
+</div>
+<p id="catch">Catch-all
+<pre id="test">
+<script class="testbody" type="text/javascript;version=1.7">
 
-<script class="testbody" type="application/javascript">
-<![CDATA[
+/** Test for Bug 157546, 417745 **/
 
-function execTests() {
-  var e = document.getElementById("edit");
-  var doc = e.contentDocument;
-  var win = e.contentWindow;
-  var root = doc.documentElement;
-  var editor = doc.body;
-  var sel = win.getSelection();
-  // Work around bug 474255 --- we need to have nonempty content before we turn on
-  // editing, or the tests below break because the editor doesn't notice when we
-  // insert non-empty content using innerHTML.
-  editor.innerHTML = "Bogus!";
-  doc.designMode='on';
-  win.focus();
+SimpleTest.waitForExplicitFinish();
 
+// This seems to be necessary because the selection is not set up properly otherwise
+setTimeout(test, 0);
+
+var eatSpace;
+
+function getPrefs() {
+  const prefSvcContractID = "@mozilla.org/preferences-service;1";
+  const prefSvcIID = Components.interfaces.nsIPrefService;
+  return Components.classes[prefSvcContractID].getService(prefSvcIID)
+                                               .getBranch("layout.word_select.");
+}
+
+function setEatSpace(newValue) {
+  getPrefs().setBoolPref("eat_space_to_next_word", newValue);
+  eatSpace = newValue;
+}
+
+function restoreEatSpace() {
+  try {
+    getPrefs().clearUserPref("eat_space_to_next_word");
+  } catch(ex) {}
+}
+
+function test() {
   netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
 
-  var eatSpace;
-
-  function getPrefs() {
-    const prefSvcContractID = "@mozilla.org/preferences-service;1";
-    const prefSvcIID = Components.interfaces.nsIPrefService;
-    return Components.classes[prefSvcContractID].getService(prefSvcIID)
-                                                 .getBranch("layout.word_select.");
-  }
-
-  function setEatSpace(newValue) {
-    getPrefs().setBoolPref("eat_space_to_next_word", newValue);
-    eatSpace = newValue;
-  }
-
-  function restoreEatSpace() {
-    try {
-      getPrefs().clearUserPref("eat_space_to_next_word");
-    } catch(ex) {}
-  }
-
-  function doCommand(cmd) {
-    var controller = document.commandDispatcher.getControllerForCommand(cmd);
-    if (controller) {
-      controller.doCommand(cmd);
-    }
-  }
+  var wordSelModifiers =
+      (navigator.platform.indexOf("Mac") >= 0) ?
+        {shiftKey:true, altKey:true} : {shiftKey:true, ctrlKey:true};
+  var sel = window.getSelection();
+  var editor = document.getElementById("editor");
 
   function testRight(node, offset) {
-    doCommand("cmd_charNext");
-    var msg = "Right movement broken in \"" + editor.innerHTML + "\", offset " + offset;
-    is(sel.anchorNode, node, msg);
-    is(sel.anchorOffset, offset, msg);
+    synthesizeKey("VK_RIGHT", {});
+    is(sel.anchorNode, node, "Right movement broken in \"" + editor.innerHTML + "\"");
+    is(sel.anchorOffset, offset, "Right movement broken in \"" + editor.innerHTML + "\"");
   }
 
   function selErrString(dir) {
@@ -65,7 +64,7 @@ function execTests() {
   }
 
   function testWordSelRight(startNode, startOffset, endNode, endOffset) {
-    doCommand("cmd_selectWordNext");
+    synthesizeKey("VK_RIGHT", wordSelModifiers);
     var selRange = sel.getRangeAt(0);
     is(selRange.startContainer, startNode, selErrString("Word right"));
     is(selRange.startOffset, startOffset, selErrString("Word right"));
@@ -74,35 +73,17 @@ function execTests() {
   }
 
   function testDelete(node, offset, text) {
-    doCommand("cmd_deleteCharForward");
-    var msg = "Delete broken in \"" + editor.innerHTML + "\", offset " + offset;
-    is(sel.anchorNode, node, msg);
-    is(sel.anchorOffset, offset, msg);
-    is(editor.textContent, text, msg);
+    synthesizeKey("VK_DELETE", {});
+    is(sel.anchorNode, node, "Delete broken in \"" + editor.innerHTML + "\"");
+    is(sel.anchorOffset, offset, "Delete broken in \"" + editor.innerHTML + "\"");
+    is(editor.textContent, text, "Delete broken in \"" + editor.innerHTML + "\"");
   }
 
   function testBackspace(node, offset, text) {
-    doCommand("cmd_deleteCharBackward");
-    var msg = "Backspace broken in \"" + editor.innerHTML + "\", offset " + offset;
-    is(sel.anchorNode, node, msg);
-    is(sel.anchorOffset, offset, msg);
-    is(editor.textContent, text, msg);
-  }
-
-  function testDeletePrevWord(node, offset, text) {
-    doCommand("cmd_deleteWordBackward");
-    var msg = "Delete previous word broken in \"" + editor.innerHTML + "\", offset " + offset;
-    is(sel.anchorNode, node, msg);
-    is(sel.anchorOffset, offset, msg);
-    is(editor.textContent, text, msg);
-  }
-
-  function testDeleteNextWord(node, offset, text) {
-    doCommand("cmd_deleteWordForward");
-    var msg = "Delete next word broken in \"" + editor.innerHTML + "\", offset " + offset;
-    is(sel.anchorNode, node, msg);
-    is(sel.anchorOffset, offset, msg);
-    is(editor.textContent, text, msg);
+    synthesizeKey("VK_BACK_SPACE", {});
+    is(sel.anchorNode, node, "Backspace broken in \"" + editor.innerHTML + "\"");
+    is(sel.anchorOffset, offset, "Backspace broken in \"" + editor.innerHTML + "\"");
+    is(editor.textContent, text, "Backspace broken in \"" + editor.innerHTML + "\"");
   }
 
   // Test cell-wise deletion of Delete
@@ -179,7 +160,7 @@ function execTests() {
 
   editor.innerHTML = "foo<div>bar</div>";
   sel.collapse(editor.firstChild, 3);
-  testDelete(editor.firstChild.nextSibling.firstChild, 3, "foobar");
+  testDelete(editor.firstChild, 3, "foobar");
 
   // Tests for Bug 419406
 
@@ -188,39 +169,11 @@ function execTests() {
   testRight(editor.firstChild, 5);
   testDelete(editor.firstChild, 5, "helloשלום");
 
-  // Tests for Bug 462188
-  editor.innerHTML = "You should not see this text.";
-  sel.collapse(editor.firstChild, 0);
-  testDeleteNextWord(editor.firstChild, 0, "\u00A0should not see this text.");
-  testDeleteNextWord(editor.firstChild, 0, "\u00A0not see this text.");
-  testDeleteNextWord(editor.firstChild, 0, "\u00A0see this text.");
-  testDeleteNextWord(editor.firstChild, 0, "\u00A0this text.");
-  testDeleteNextWord(editor.firstChild, 0, "\u00A0text.");
-  testDeleteNextWord(editor, 0, "");
-
-  editor.innerHTML = "You should not see this text.";
-  sel.collapse(editor.firstChild, 29);
-  testDeletePrevWord(editor.firstChild, 24, "You should not see this ");
-  testDeletePrevWord(editor.firstChild, 19, "You should not see ");
-  testDeletePrevWord(editor.firstChild, 15, "You should not ");
-  testDeletePrevWord(editor.firstChild, 11, "You should ");
-  testDeletePrevWord(editor.firstChild,  4, "You ");
-  testDeletePrevWord(editor,  0, "");
-
   SimpleTest.finish();
 }
 
-SimpleTest.waitForExplicitFinish();
-addLoadEvent(execTests);
-]]>
+
 </script>
-
-<body  id="html_body" xmlns="http://www.w3.org/1999/xhtml">
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=462188">Mozilla Bug 462188</a>
-<p id="display"></p>
-
-<pre id="test">
 </pre>
-<iframe id="edit" width="200" height="100" src="about:blank"/>
 </body>
-</window>
+</html>