diff -r 000000000000 -r 6474c204b198 browser/components/tabview/content.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/tabview/content.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,83 @@
+/* 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/. */
+
+"use strict";
+
+let Cu = Components.utils;
+let Ci = Components.interfaces;
+
+Cu.import("resource:///modules/tabview/utils.jsm");
+
+// Bug 671101 - directly using webProgress in this context
+// causes docShells to leak
+this.__defineGetter__("webProgress", function () {
+  let ifaceReq = docShell.QueryInterface(Ci.nsIInterfaceRequestor);
+  return ifaceReq.getInterface(Ci.nsIWebProgress);
+});
+
+// ----------
+// WindowEventHandler
+//
+// Handles events dispatched by the content window.
+let WindowEventHandler = {
+  // ----------
+  // Function: onDOMWillOpenModalDialog
+  // Sends a synchronous message when the "onDOMWillOpenModalDialog" event
+  // is fired right before a modal dialog will be opened by the current page.
+  onDOMWillOpenModalDialog: function WEH_onDOMWillOpenModalDialog(event) {
+    // (event.isTrusted == true) when the event is generated by a user action
+    // and does not originate from a script.
+    if (!event.isTrusted)
+      return;
+
+    // we're intentionally sending a synchronous message to handle this event
+    // as quick as possible, switch the selected tab and hide the tabview
+    // before the modal dialog is shown
+    sendSyncMessage("Panorama:DOMWillOpenModalDialog");
+  },
+
+  // ----------
+  // Function: onMozAfterPaint
+  // Sends an asynchronous message when the "onMozAfterPaint" event
+  // is fired.
+  onMozAfterPaint: function WEH_onMozAfterPaint(event) {
+    if (event.clientRects.length > 0) {
+      sendAsyncMessage("Panorama:MozAfterPaint");
+    }
+  }
+};
+
+// add event listeners
+addEventListener("DOMWillOpenModalDialog", WindowEventHandler.onDOMWillOpenModalDialog, false);
+addEventListener("MozAfterPaint", WindowEventHandler.onMozAfterPaint, false);
+
+// ----------
+// WindowMessageHandler
+//
+// Handles messages sent by the chrome process.
+let WindowMessageHandler = {
+  // ----------
+  // Function: isDocumentLoaded
+  // Checks if the currently active document is loaded.
+  isDocumentLoaded: function WMH_isDocumentLoaded(cx) {
+    let isLoaded = (content.document.readyState != "uninitialized" &&
+                    !webProgress.isLoadingDocument);
+
+    sendAsyncMessage(cx.name, {isLoaded: isLoaded});
+  },
+
+  // ----------
+  // Function: isImageDocument
+  // Checks if the currently active document is an image document or not.
+  isImageDocument: function WMH_isImageDocument(cx) {
+    let isImageDocument = (content.document instanceof Ci.nsIImageDocument);
+
+    sendAsyncMessage(cx.name, {isImageDocument: isImageDocument});
+  }
+};
+
+// add message listeners
+addMessageListener("Panorama:isDocumentLoaded", WindowMessageHandler.isDocumentLoaded);
+addMessageListener("Panorama:isImageDocument", WindowMessageHandler.isImageDocument);
+