Replace FFmpegDemuxer thread per element with base::TaskScheduler.

chromecast/media/cma/test/frame_segmenter_for_test.cc

 // Copyright 2014 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 "chromecast/media/cma/test/frame_segmenter_for_test.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_scheduler.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chromecast/media/cma/base/decoder_buffer_adapter.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/demuxer.h"
 #include "media/base/media_log.h"
 #include "media/base/media_tracks.h"
 #include "media/base/test_helpers.h"
 #include "media/filters/ffmpeg_demuxer.h"
 #include "media/filters/file_data_source.h"
 #include "media/filters/h264_parser.h"
@@ skipping 283 matching lines @@
 
 DemuxResult::~DemuxResult() {
 }
 
 DemuxResult FFmpegDemuxForTest(const base::FilePath& filepath,
                                bool audio) {
   FakeDemuxerHost fake_demuxer_host;
   ::media::FileDataSource data_source;
   CHECK(data_source.Initialize(filepath));
 
+  base::test::ScopedTaskScheduler task_scheduler(base::MessageLoop::current());

[gab, 2017/02/26 18:01:35]

There should really just be one ScopedTaskScheduler in the whole scope of a
test, bringing it in&out in a helper method is unexpected.

Can we put one in the fixture of audio_video_pipeline_device_unittest.cc where
this seems to be used instead?

[DaleCurtis, 2017/02/27 21:26:30]

Done, but took a few more changes.

   ::media::FFmpegDemuxer demuxer(
       base::ThreadTaskRunnerHandle::Get(), &data_source,
       base::Bind(&OnEncryptedMediaInitData), base::Bind(&OnMediaTracksUpdated),
       new ::media::MediaLog());
   ::media::WaitableMessageLoopEvent init_event;
   demuxer.Initialize(&fake_demuxer_host,
                      init_event.GetPipelineStatusCB(),
                      false);
   init_event.RunAndWaitForStatus(::media::PIPELINE_OK);
 
@@ skipping 19 matching lines @@
     CHECK(!demux_result.frames.empty());
     end_of_stream = demux_result.frames.back()->end_of_stream();
   }
 
   demuxer.Stop();
   return demux_result;
 }
 
 }  // namespace media
 }  // namespace chromecast