Switching AudioOutputAuthorizationHandler from using AudioManager interface to AudioSystem one.

BUG=672468
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2692203003
Cr-Commit-Position: refs/heads/master@{#450939}
  void SyncWithAudioThread() {
    base::RunLoop().RunUntilIdle();

    base::RunLoop run_loop;
    audio_manager_->GetTaskRunner()->PostTask(
        FROM_HERE, media::BindToCurrentLoop(run_loop.QuitClosure()));
    run_loop.Run();
  }

  void SyncWithAudioThread() {
    base::RunLoop().RunUntilIdle();

    base::RunLoop run_loop;
    audio_manager_->GetTaskRunner()->PostTask(
        FROM_HERE, media::BindToCurrentLoop(run_loop.QuitClosure()));
    run_loop.Run();
  }
