Revert of Replace FFmpegDemuxer thread per element with base::TaskScheduler.

media/base/demuxer_perftest.cc

Index: media/base/demuxer_perftest.cc
diff --git a/media/base/demuxer_perftest.cc b/media/base/demuxer_perftest.cc
index b04db50b47e65cd30e295ae24f2249045a247ae0..45b449912b66321977428dc4c39a6743dc406ff1 100644
--- a/media/base/demuxer_perftest.cc
+++ b/media/base/demuxer_perftest.cc
@@ -12,7 +12,6 @@
 #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"
@@ -49,19 +48,20 @@
   DISALLOW_COPY_AND_ASSIGN(DemuxerHostImpl);
 };
 
-static void QuitLoopWithStatus(base::Closure quit_cb,
+static void QuitLoopWithStatus(base::MessageLoop* message_loop,
                                media::PipelineStatus status) {
   CHECK_EQ(status, media::PIPELINE_OK);
-  quit_cb.Run();
+  message_loop->task_runner()->PostTask(
+      FROM_HERE, base::MessageLoop::QuitWhenIdleClosure());
 }
 
 static void OnEncryptedMediaInitData(EmeInitDataType init_data_type,
                                      const std::vector<uint8_t>& init_data) {
-  DVLOG(1) << "File is encrypted.";
+  VLOG(0) << "File is encrypted.";
 }
 
 static void OnMediaTracksUpdated(std::unique_ptr<MediaTracks> tracks) {
-  DVLOG(1) << "Got media tracks info, tracks = " << tracks->tracks().size();
+  VLOG(0) << "Got media tracks info, tracks = " << tracks->tracks().size();
 }
 
 typedef std::vector<media::DemuxerStream* > Streams;
@@ -177,10 +177,10 @@
 
 static void RunDemuxerBenchmark(const std::string& filename) {
   base::FilePath file_path(GetTestDataFilePath(filename));
-  base::TimeDelta total_time;
+  double total_time = 0.0;
   for (int i = 0; i < kBenchmarkIterations; ++i) {
     // Setup.
-    base::test::ScopedTaskScheduler scoped_task_scheduler;
+    base::MessageLoop message_loop;
     DemuxerHostImpl demuxer_host;
     FileDataSource data_source;
     ASSERT_TRUE(data_source.Initialize(file_path));
@@ -189,32 +189,34 @@
         base::Bind(&OnEncryptedMediaInitData);
     Demuxer::MediaTracksUpdatedCB tracks_updated_cb =
         base::Bind(&OnMediaTracksUpdated);
-    FFmpegDemuxer demuxer(base::ThreadTaskRunnerHandle::Get(), &data_source,
+    FFmpegDemuxer demuxer(message_loop.task_runner(), &data_source,
                           encrypted_media_init_data_cb, tracks_updated_cb,
                           new MediaLog());
 
-    {
-      base::RunLoop run_loop;
-      demuxer.Initialize(
-          &demuxer_host,
-          base::Bind(&QuitLoopWithStatus, run_loop.QuitClosure()), false);
-      run_loop.Run();
-    }
-
+    demuxer.Initialize(&demuxer_host,
+                       base::Bind(&QuitLoopWithStatus, &message_loop),
+                       false);
+    base::RunLoop().Run();
     StreamReader stream_reader(&demuxer, false);
 
     // Benchmark.
     base::TimeTicks start = base::TimeTicks::Now();
-    while (!stream_reader.IsDone())
+    while (!stream_reader.IsDone()) {
       stream_reader.Read();
-    total_time += base::TimeTicks::Now() - start;
+    }
+    base::TimeTicks end = base::TimeTicks::Now();
+    total_time += (end - start).InSecondsF();
     demuxer.Stop();
-    base::RunLoop().RunUntilIdle();
-  }
-
-  perf_test::PrintResult("demuxer_bench", "", filename,
-                         kBenchmarkIterations / total_time.InSecondsF(),
-                         "runs/s", true);
+    QuitLoopWithStatus(&message_loop, PIPELINE_OK);
+    base::RunLoop().Run();
+  }
+
+  perf_test::PrintResult("demuxer_bench",
+                         "",
+                         filename,
+                         kBenchmarkIterations / total_time,
+                         "runs/s",
+                         true);
 }
 
 #if defined(OS_WIN)