diff -r 000000000000 -r 6474c204b198 content/canvas/src/WebGLContextLossTimer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/canvas/src/WebGLContextLossTimer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "WebGLContext.h"
+
+using namespace mozilla;
+
+/* static */ void
+WebGLContext::RobustnessTimerCallbackStatic(nsITimer* timer, void *thisPointer) {
+    static_cast<WebGLContext*>(thisPointer)->RobustnessTimerCallback(timer);
+}
+
+void
+WebGLContext::SetupContextLossTimer() {
+    // If the timer was already running, don't restart it here. Instead,
+    // wait until the previous call is done, then fire it one more time.
+    // This is an optimization to prevent unnecessary cross-communication
+    // between threads.
+    if (mContextLossTimerRunning) {
+        mDrawSinceContextLossTimerSet = true;
+        return;
+    }
+
+    mContextRestorer->InitWithFuncCallback(RobustnessTimerCallbackStatic,
+                                            static_cast<void*>(this),
+                                            1000,
+                                            nsITimer::TYPE_ONE_SHOT);
+    mContextLossTimerRunning = true;
+    mDrawSinceContextLossTimerSet = false;
+}
+
+void
+WebGLContext::TerminateContextLossTimer() {
+    if (mContextLossTimerRunning) {
+        mContextRestorer->Cancel();
+        mContextLossTimerRunning = false;
+    }
+}