Bug 1479309: Don't load shield-content-frame.js until needed. r=mythmon

MozReview-Commit-ID: 5usNkHYjifd

--HG--
rename : toolkit/components/normandy/content/shield-content-frame.js => toolkit/components/normandy/content/ShieldFrameListener.jsm
extra : rebase_source : 519b450e365166d4e377083c5a926ad07d167fc7

toolkit/components/normandy/content/AboutPages.jsm

@@ -21,14 +21,7 @@ var EXPORTED_SYMBOLS = ["AboutPages"];
 
 const SHIELD_LEARN_MORE_URL_PREF = "app.normandy.shieldLearnMoreUrl";
 
-// Due to bug 1051238 frame scripts are cached forever, so we can't update them
+const PROCESS_SCRIPT = "resource://normandy-content/shield-content-process.js";
-// as a restartless add-on. The Math.random() is the work around for this.
-const PROCESS_SCRIPT = (
-  `resource://normandy-content/shield-content-process.js?${Math.random()}`
-);
-const FRAME_SCRIPT = (
-  `resource://normandy-content/shield-content-frame.js?${Math.random()}`
-);
 
 /**
  * Class for managing an about: page that Normandy provides. Adapted from
@@ -99,7 +92,6 @@ var AboutPages = {
   async init() {
     // Load scripts in content processes and tabs
     Services.ppmm.loadProcessScript(PROCESS_SCRIPT, true);
-    Services.mm.loadFrameScript(FRAME_SCRIPT, true);
 
     // Register about: pages and their listeners
     this.aboutStudies.register();
@@ -109,7 +101,6 @@ var AboutPages = {
       // Stop loading processs scripts and notify existing scripts to clean up.
       Services.ppmm.removeDelayedProcessScript(PROCESS_SCRIPT);
       Services.ppmm.broadcastAsyncMessage("Shield:ShuttingDown");
-      Services.mm.removeDelayedFrameScript(FRAME_SCRIPT);
       Services.mm.broadcastAsyncMessage("Shield:ShuttingDown");
 
       // Clean up about pages

toolkit/components/normandy/content/ShieldFrameListener.jsm

@@ -3,6 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
+var EXPORTED_SYMBOLS = ["ShieldFrameListener"];
+
 /**
  * Listen for DOM events bubbling up from the about:studies page, and perform
  * privileged actions in response to them. If we need to do anything that the
@@ -13,11 +15,8 @@
  * is opened.
  */
 
-/* global content addMessageListener removeMessageListener sendAsyncMessage */
-
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
-ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 
 const frameGlobal = {};
 ChromeUtils.defineModuleGetter(
@@ -38,6 +37,10 @@ XPCOMUtils.defineLazyGetter(this, "gStringBundle", function() {
  * @implements EventListener
  */
 class ShieldFrameListener {
+  constructor(mm) {
+    this.mm = mm;
+  }
+
   handleEvent(event) {
     // Abort if the current page isn't about:studies.
     if (!this.ensureTrustedOrigin()) {
@@ -46,23 +49,23 @@ class ShieldFrameListener {
 
     // We waited until after we received an event to register message listeners
     // in order to save resources for tabs that don't ever load about:studies.
-    addMessageListener("Shield:ShuttingDown", this);
+    this.mm.addMessageListener("Shield:ShuttingDown", this);
-    addMessageListener("Shield:ReceiveStudyList", this);
+    this.mm.addMessageListener("Shield:ReceiveStudyList", this);
-    addMessageListener("Shield:ReceiveStudiesEnabled", this);
+    this.mm.addMessageListener("Shield:ReceiveStudiesEnabled", this);
 
     switch (event.detail.action) {
       // Actions that require the parent process
       case "GetRemoteValue:StudyList":
-        sendAsyncMessage("Shield:GetStudyList");
+        this.mm.sendAsyncMessage("Shield:GetStudyList");
         break;
       case "RemoveStudy":
-        sendAsyncMessage("Shield:RemoveStudy", event.detail.data);
+        this.mm.sendAsyncMessage("Shield:RemoveStudy", event.detail.data);
         break;
       case "GetRemoteValue:StudiesEnabled":
-        sendAsyncMessage("Shield:GetStudiesEnabled");
+        this.mm.sendAsyncMessage("Shield:GetStudiesEnabled");
         break;
       case "NavigateToDataPreferences":
-        sendAsyncMessage("Shield:OpenDataPreferences");
+        this.mm.sendAsyncMessage("Shield:OpenDataPreferences");
         break;
       // Actions that can be performed in the content process
       case "GetRemoteValue:ShieldLearnMoreHref":
@@ -94,7 +97,7 @@ class ShieldFrameListener {
    * @return {Boolean}
    */
   ensureTrustedOrigin() {
-    return content.document.documentURI.startsWith("about:studies");
+    return this.mm.content.document.documentURI.startsWith("about:studies");
   }
 
   /**
@@ -127,6 +130,8 @@ class ShieldFrameListener {
       return;
     }
 
+    let {content} = this.mm;
+
     // Clone details and use the event class from the unprivileged context.
     const event = new content.document.defaultView.CustomEvent(type, {
       bubbles: true,
@@ -136,10 +141,8 @@ class ShieldFrameListener {
   }
 
   onShutdown() {
-    removeMessageListener("Shield:SendStudyList", this);
+    this.mm.removeMessageListener("Shield:SendStudyList", this);
-    removeMessageListener("Shield:ShuttingDown", this);
+    this.mm.removeMessageListener("Shield:ShuttingDown", this);
-    removeEventListener("Shield", this);
+    this.mm.removeEventListener("Shield", this);
   }
 }
-
-addEventListener("ShieldPageEvent", new ShieldFrameListener(), false, true);

toolkit/content/browser-content.js

@@ -37,6 +37,12 @@ XPCOMUtils.defineLazyProxy(this, "PopupBlocking", () => {
   return new tmp.PopupBlocking(global);
 });
 
+XPCOMUtils.defineLazyProxy(this, "ShieldFrameListener", () => {
+  let tmp = {};
+  ChromeUtils.import("resource://normandy-content/ShieldFrameListener.jsm", tmp);
+  return new tmp.ShieldFrameListener(global);
+});
+
 XPCOMUtils.defineLazyProxy(this, "SelectionSourceContent",
   "resource://gre/modules/SelectionSourceContent.jsm");
 
@@ -534,3 +540,5 @@ let ExtFind = {
 };
 
 ExtFind.init();
+
+addEventListener("ShieldPageEvent", ShieldFrameListener, false, true);