Fixed AudioInputController muted state related tsan bug.

media/audio/audio_input_controller.h

Index: media/audio/audio_input_controller.h
diff --git a/media/audio/audio_input_controller.h b/media/audio/audio_input_controller.h
index 2b8669c27555e9db338f381e0d98af83f694e62a..2711fdb11b290f592d163f96f93fba8c458902e0 100644
--- a/media/audio/audio_input_controller.h
+++ b/media/audio/audio_input_controller.h
@@ -378,7 +378,10 @@ class MEDIA_EXPORT AudioInputController
   base::TimeTicks stream_create_time_;
 
   bool is_muted_ = false;
-  base::RepeatingTimer check_muted_state_timer_;
+
+  // Timer cannot be destroyed in destructor, due to threading, so keep it in an
+  // Optional.
+  base::Optional<base::RepeatingTimer> check_muted_state_timer_;
 
 #if BUILDFLAG(ENABLE_WEBRTC)
   // Used for audio debug recordings. Accessed on audio thread.