Actually return black for ReadPixelsSync() on Mac.

media/filters/gpu_video_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/gpu_video_decoder.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 384 matching lines @@
   event->Signal();
 }
 
 static void ReadPixelsSync(
     const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
     uint32 texture_id,
     const gfx::Rect& visible_rect,
     const SkBitmap& pixels) {
 #if defined(OS_MACOSX)
   // For Mac OS X, just return black. http://crbug.com/425708.
-  pixels.eraseARGB(255, 0, 255, 0);
+  pixels.eraseARGB(0, 0, 0, 0);
   return;
 #endif
 
   base::WaitableEvent event(true, false);
   if (!factories->GetTaskRunner()->PostTask(FROM_HERE,
                                             base::Bind(&ReadPixelsSyncInner,
                                                        factories,
                                                        texture_id,
                                                        visible_rect,
                                                        pixels,
@@ skipping 212 matching lines @@
   DLOG(ERROR) << "VDA Error: " << error;
   DestroyVDA();
 }
 
 void GpuVideoDecoder::DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent()
     const {
   DCHECK(factories_->GetTaskRunner()->BelongsToCurrentThread());
 }
 
 }  // namespace media