Pass in media message loop to VideoRendererBase and enforce calling on the right thread.

media/media.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
     # Override to dynamically link the PulseAudio library.
     'use_pulseaudio%': 0,
     # Override to dynamically link the cras (ChromeOS audio) library.
@@ skipping 174 matching lines @@
         'base/audio_timestamp_helper.cc',
         'base/audio_timestamp_helper.h',
         'base/bind_to_loop.h',
         'base/bitstream_buffer.h',
         'base/bit_reader.cc',
         'base/bit_reader.h',
         'base/buffers.cc',
         'base/buffers.h',
         'base/byte_queue.cc',
         'base/byte_queue.h',
+        'base/callback_wrapper.h',
         'base/channel_mixer.cc',
         'base/channel_mixer.h',
         'base/clock.cc',
         'base/clock.h',
         'base/data_buffer.cc',
         'base/data_buffer.h',
         'base/data_source.cc',
         'base/data_source.h',
         'base/decoder_buffer.cc',
         'base/decoder_buffer.h',
@@ skipping 1145 matching lines @@
             'media',
           ],
           'sources': [
             'tools/media_bench/media_bench.cc',
           ],
         },
       ],
     }]
   ],
 }