media::FFmpegVideoDecoder: remove ctor param |task_runner| and use a ThreadChecker instead.

media/test/pipeline_integration_test_base.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/test/pipeline_integration_test_base.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_vector.h"
 #include "media/base/cdm_context.h"
 #include "media/base/media_log.h"
@@ skipping 218 matching lines @@
 }
 
 scoped_ptr<Renderer> PipelineIntegrationTestBase::CreateRenderer() {
   ScopedVector<VideoDecoder> video_decoders;
 #if !defined(MEDIA_DISABLE_LIBVPX)
   video_decoders.push_back(
       new VpxVideoDecoder(message_loop_.task_runner()));
 #endif  // !defined(MEDIA_DISABLE_LIBVPX)
 
 #if !defined(MEDIA_DISABLE_FFMPEG)
-  video_decoders.push_back(
-      new FFmpegVideoDecoder(message_loop_.task_runner()));
+  video_decoders.push_back(new FFmpegVideoDecoder());
 #endif
 
   // Simulate a 60Hz rendering sink.
   video_sink_.reset(new NullVideoSink(
       clockless_playback_, base::TimeDelta::FromSecondsD(1.0 / 60),
       base::Bind(&PipelineIntegrationTestBase::OnVideoFramePaint,
                  base::Unretained(this)),
       message_loop_.task_runner()));
 
   // Disable frame dropping if hashing is enabled.
@@ skipping 86 matching lines @@
   DCHECK(clockless_playback_);
   return clockless_audio_sink_->render_time();
 }
 
 base::TimeTicks DummyTickClock::NowTicks() {
   now_ += base::TimeDelta::FromSeconds(60);
   return now_;
 }
 
 }  // namespace media