Replace FFmpegDemuxer thread per element with base::TaskScheduler.

media/base/run_all_perftests.cc

Index: media/base/run_all_perftests.cc
diff --git a/media/base/run_all_perftests.cc b/media/base/run_all_perftests.cc
index 54ce21b40af118a62d06948628b422c6767c1936..f41edc5f241f0ad88a50148bca2564a1d447a504 100644
--- a/media/base/run_all_perftests.cc
+++ b/media/base/run_all_perftests.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/bind.h"
+#include "base/task_scheduler/task_scheduler.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "build/build_config.h"
@@ -24,6 +25,8 @@ void TestSuiteNoAtExit::Initialize() {
   // Run this here instead of main() to ensure an AtExitManager is already
   // present.
   media::InitializeMediaLibrary();
+
+  base::TaskScheduler::CreateAndSetSimpleTaskScheduler(1);

[gab, 2017/02/23 21:37:09]

For tests see base::test::ScopedTaskScheduler, also you inspired me to make this
documentation clearer https://codereview.chromium.org/2709163006/ :). Anymore
feedback you have on things that were unclear is welcome!

[DaleCurtis, 2017/02/23 23:07:06]

Thanks! Switched, though I think this omits a bit of test coverage since by
forcing an additional thread we get coverage on potential races that the fake
task scheduler will not provide by using the same message loop as the test
control functionality.

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

You can use ScopedAsyncTaskScheduler if you want that behavior :).

The reasoning behind ScopedTaskScheduler using the main thread is that it allows
determinism in unit tests (and thus simplicity). IMO fuzzing/testing races is
more the role of browser/integration tests.

 }
 
 int main(int argc, char** argv) {