Bug 1470023: Lazily load PluginContent.jsm when it's first required. r=felipe

MozReview-Commit-ID: 2n9NP5mEEcG

--HG--
extra : rebase_source : 4357e78d02e7c3f6af6cfea1e0681e50476bddcb
extra : source : 064e448df638efc4a99fdf9f400d1eac2b7505ca

browser/base/content/content.js

@@ -317,8 +317,70 @@ ClickEventHandler.init();
 ContentLinkHandler.init(this);
 ContentMetaHandler.init(this);
 
-// TODO: Load this lazily so the JSM is run only if a relevant event/message fires.
-void new PluginContent(global);
+var PluginContentStub = {
+  EVENTS: [
+    "PluginCrashed",
+    "PluginOutdated",
+    "PluginInstantiated",
+    "PluginRemoved",
+    "HiddenPlugin",
+  ],
+
+  MESSAGES: [
+    "BrowserPlugins:ActivatePlugins",
+    "BrowserPlugins:NotificationShown",
+    "BrowserPlugins:ContextMenuCommand",
+    "BrowserPlugins:NPAPIPluginProcessCrashed",
+    "BrowserPlugins:CrashReportSubmitted",
+    "BrowserPlugins:Test:ClearCrashData",
+  ],
+
+  _pluginContent: null,
+  get pluginContent() {
+    if (!this._pluginContent) {
+      this._pluginContent = new PluginContent(global);
+    }
+    return this._pluginContent;
+  },
+
+  init() {
+    addEventListener("unload", this);
+
+    addEventListener("PluginBindingAttached", this, true, true);
+
+    for (let event of this.EVENTS) {
+      addEventListener(event, this, true);
+    }
+    for (let msg of this.MESSAGES) {
+      addMessageListener(msg, this);
+    }
+    Services.obs.addObserver(this, "decoder-doctor-notification");
+  },
+
+  uninit() {
+    Services.obs.removeObserver(this, "decoder-doctor-notification");
+  },
+
+  observe(subject, topic, data) {
+    return this.pluginContent.observe(subject, topic, data);
+  },
+
+  handleEvent(event) {
+    if (event.type === "unload") {
+      return this.uninit();
+    }
+    return this.pluginContent.handleEvent(event);
+  },
+
+  receiveMessage(msg) {
+    return this.pluginContent.receiveMessage(msg);
+  },
+};
+
+PluginContentStub.init();
+
+// This is a temporary hack to prevent regressions.
+void content;
 
 addEventListener("DOMWindowFocus", function(event) {
   sendAsyncMessage("DOMWindowFocus", {});

browser/components/extensions/parent/ext-tabs.js

@@ -76,7 +76,7 @@ let tabListener = {
   },
 
   onLocationChange(browser, webProgress, request, locationURI, flags) {
-    if (webProgress.isTopLevel) {
+    if (webProgress.isTopLevel && locationURI.spec !== "about:blank") {
       let {gBrowser} = browser.ownerGlobal;
       let nativeTab = gBrowser.getTabForBrowser(browser);
 
@@ -596,7 +596,9 @@ this.tabs = class extends ExtensionAPI {
               window.focusAndSelectUrlBar();
             }
 
-            if (createProperties.url && createProperties.url !== window.BROWSER_NEW_TAB_URL) {
+            if (createProperties.url &&
+                createProperties.url !== "about:blank" &&
+                createProperties.url !== window.BROWSER_NEW_TAB_URL) {
               // We can't wait for a location change event for about:newtab,
               // since it may be pre-rendered, in which case its initial
               // location change event has already fired.

browser/modules/PluginContent.jsm

@@ -42,51 +42,8 @@ PluginContent.prototype = {
     // Cache of plugin crash information sent from the parent
     this.pluginCrashData = new Map();
 
-    // Note that the XBL binding is untrusted
-    global.addEventListener("PluginBindingAttached", this, true, true);
-    global.addEventListener("PluginCrashed", this, true);
-    global.addEventListener("PluginOutdated", this, true);
-    global.addEventListener("PluginInstantiated", this, true);
-    global.addEventListener("PluginRemoved", this, true);
     global.addEventListener("pagehide", this, true);
     global.addEventListener("pageshow", this, true);
-    global.addEventListener("unload", this);
-    global.addEventListener("HiddenPlugin", this, true);
-
-    global.addMessageListener("BrowserPlugins:ActivatePlugins", this);
-    global.addMessageListener("BrowserPlugins:NotificationShown", this);
-    global.addMessageListener("BrowserPlugins:ContextMenuCommand", this);
-    global.addMessageListener("BrowserPlugins:NPAPIPluginProcessCrashed", this);
-    global.addMessageListener("BrowserPlugins:CrashReportSubmitted", this);
-    global.addMessageListener("BrowserPlugins:Test:ClearCrashData", this);
-
-    Services.obs.addObserver(this, "decoder-doctor-notification");
-  },
-
-  uninit() {
-    let global = this.global;
-
-    global.removeEventListener("PluginBindingAttached", this, true);
-    global.removeEventListener("PluginCrashed", this, true);
-    global.removeEventListener("PluginOutdated", this, true);
-    global.removeEventListener("PluginInstantiated", this, true);
-    global.removeEventListener("PluginRemoved", this, true);
-    global.removeEventListener("pagehide", this, true);
-    global.removeEventListener("pageshow", this, true);
-    global.removeEventListener("unload", this);
-    global.removeEventListener("HiddenPlugin", this, true);
-
-    global.removeMessageListener("BrowserPlugins:ActivatePlugins", this);
-    global.removeMessageListener("BrowserPlugins:NotificationShown", this);
-    global.removeMessageListener("BrowserPlugins:ContextMenuCommand", this);
-    global.removeMessageListener("BrowserPlugins:NPAPIPluginProcessCrashed", this);
-    global.removeMessageListener("BrowserPlugins:CrashReportSubmitted", this);
-    global.removeMessageListener("BrowserPlugins:Test:ClearCrashData", this);
-
-    Services.obs.removeObserver(this, "decoder-doctor-notification");
-
-    delete this.global;
-    delete this.content;
   },
 
   receiveMessage(msg) {
@@ -444,11 +401,6 @@ PluginContent.prototype = {
   handleEvent(event) {
     let eventType = event.type;
 
-    if (eventType == "unload") {
-      this.uninit();
-      return;
-    }
-
     if (eventType == "pagehide") {
       this.onPageHide(event);
       return;