Add a hang monitor for the audio thread.

media/audio/audio_manager.h

Index: media/audio/audio_manager.h
diff --git a/media/audio/audio_manager.h b/media/audio/audio_manager.h
index 7705cdb804ee516b254beb0fe8d35d51a61f738c..5e49b8b399afd138c35f659d73823be06a0e9567 100644
--- a/media/audio/audio_manager.h
+++ b/media/audio/audio_manager.h
@@ -34,6 +34,13 @@ class MEDIA_EXPORT AudioManager {
   // such |audio_log_factory| must outlive the AudioManager.
   static AudioManager* Create(AudioLogFactory* audio_log_factory);
 
+  // Similar to Create() except also schedules a monitor on the given task
+  // runner to ensure the audio thread is not stuck for more than 60 seconds; if
+  // a hang is detected, the process will be crashed.
+  static AudioManager* CreateWithHangTimer(
+      AudioLogFactory* audio_log_factory,
+      const scoped_refptr<base::SingleThreadTaskRunner>& monitor_task_runner);
+
   // Similar to Create() except uses a FakeAudioLogFactory for testing.
   static AudioManager* CreateForTesting();