diff -r 000000000000 -r 6474c204b198 gfx/gl/ForceDiscreteGPUHelperCGL.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/gl/ForceDiscreteGPUHelperCGL.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+/* -*- 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/. */
+
+#ifndef ForceDiscreteGPUHelperCGL_h_
+#define ForceDiscreteGPUHelperCGL_h_
+
+#include <OpenGL/OpenGL.h>
+
+/** This RAII helper guarantees that we're on the discrete GPU during its lifetime.
+ * 
+ * As long as any ForceDiscreteGPUHelperCGL object is alive, we're on the discrete GPU.
+ */
+class ForceDiscreteGPUHelperCGL
+{
+    CGLPixelFormatObj mPixelFormatObj;
+
+public:
+    ForceDiscreteGPUHelperCGL()
+    {
+        // the code in this function is taken from Chromium, src/ui/gfx/gl/gl_context_cgl.cc, r122013
+        // BSD-style license, (c) The Chromium Authors
+        CGLPixelFormatAttribute attribs[1];
+        attribs[0] = static_cast<CGLPixelFormatAttribute>(0);
+        GLint num_pixel_formats = 0;
+        CGLChoosePixelFormat(attribs, &mPixelFormatObj, &num_pixel_formats);
+    }
+
+    ~ForceDiscreteGPUHelperCGL()
+    {
+        CGLReleasePixelFormat(mPixelFormatObj);
+    }
+};
+
+#endif // ForceDiscreteGPUHelperCGL_h_