Replace FFmpegDemuxer thread per element with base::TaskScheduler.

media/base/demuxer_perftest.cc

 // Copyright 2013 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 <stddef.h>
 #include <stdint.h>
 #include <memory>
 
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/test/scoped_task_scheduler.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "media/base/media.h"
 #include "media/base/media_log.h"
 #include "media/base/media_tracks.h"
 #include "media/base/test_data_util.h"
 #include "media/base/timestamp_constants.h"
 #include "media/filters/ffmpeg_demuxer.h"
 #include "media/filters/file_data_source.h"
@@ skipping 153 matching lines @@
 static void RunDemuxerBenchmark(const std::string& filename) {
   base::FilePath file_path(GetTestDataFilePath(filename));
   double total_time = 0.0;
   for (int i = 0; i < kBenchmarkIterations; ++i) {
     // Setup.
     base::MessageLoop message_loop;
     DemuxerHostImpl demuxer_host;
     FileDataSource data_source;
     ASSERT_TRUE(data_source.Initialize(file_path));
 
+    base::test::ScopedTaskScheduler scoped_task_scheduler(&message_loop);
     Demuxer::EncryptedMediaInitDataCB encrypted_media_init_data_cb =
         base::Bind(&OnEncryptedMediaInitData);
     Demuxer::MediaTracksUpdatedCB tracks_updated_cb =
         base::Bind(&OnMediaTracksUpdated);
     FFmpegDemuxer demuxer(message_loop.task_runner(), &data_source,
                           encrypted_media_init_data_cb, tracks_updated_cb,
                           new MediaLog());
 
     demuxer.Initialize(&demuxer_host,
                        base::Bind(&QuitLoopWithStatus, &message_loop),

[gab, 2017/02/24 01:09:05]

Use RunLoop::QuitClosure() (from the RunLoop on 213 -- i.e. instantiate it above
and still Run() it below).

Then you can use the implicit MessageLoop from ScopedTaskScheduler

[DaleCurtis, 2017/02/24 23:40:29]

Done.

                        false);
     base::RunLoop().Run();
     StreamReader stream_reader(&demuxer, false);
 
     // Benchmark.
     base::TimeTicks start = base::TimeTicks::Now();
     while (!stream_reader.IsDone()) {
       stream_reader.Read();
     }
     base::TimeTicks end = base::TimeTicks::Now();
@@ skipping 25 matching lines @@
 #if BUILDFLAG(USE_PROPRIETARY_CODECS)
   RunDemuxerBenchmark("bear-1280x720.mp4");
   RunDemuxerBenchmark("sfx.mp3");
 #endif
 #if BUILDFLAG(USE_PROPRIETARY_CODECS) && defined(OS_CHROMEOS)
   RunDemuxerBenchmark("bear.avi");
 #endif
 }
 
 }  // namespace media