Remove mock_ffmpeg and update media unittests.

media/filters/ffmpeg_video_decoder_unittest.cc

Index: media/filters/ffmpeg_video_decoder_unittest.cc
diff --git a/media/filters/ffmpeg_video_decoder_unittest.cc b/media/filters/ffmpeg_video_decoder_unittest.cc
index 7614d8b71591e277916dfe9c85675c9ba8f3b87a..e3dd90d39cb67e41987c0a42bbce009593c3061b 100644
--- a/media/filters/ffmpeg_video_decoder_unittest.cc
+++ b/media/filters/ffmpeg_video_decoder_unittest.cc
@@ -10,7 +10,6 @@
 #include "media/base/data_buffer.h"
 #include "media/base/filters.h"
 #include "media/base/mock_callback.h"
-#include "media/base/mock_ffmpeg.h"
 #include "media/base/mock_filter_host.h"
 #include "media/base/mock_filters.h"
 #include "media/base/mock_task.h"
@@ -220,7 +219,6 @@ class FFmpegVideoDecoderTest : public testing::Test {
   AVCodec codec_;
   AVFrame yuv_frame_;
   scoped_refptr<VideoFrame> video_frame_;
-  StrictMock<MockFFmpeg> mock_ffmpeg_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FFmpegVideoDecoderTest);