Freeze the reported media time while audio is restarted

media/renderers/renderer_impl.h

Index: media/renderers/renderer_impl.h
diff --git a/media/renderers/renderer_impl.h b/media/renderers/renderer_impl.h
index e400e8ac161675608a38b74af23fe3d876b462f6..aae8b52aa7dfc46660ace4d84237f1c44e531d8b 100644
--- a/media/renderers/renderer_impl.h
+++ b/media/renderers/renderer_impl.h
@@ -229,7 +229,14 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   // runs out of data but the audio renderer still has enough.
   base::TimeDelta video_underflow_threshold_;
 
+  // Lock used to protect access to the |restarting_audio_| flag and
+  // |restarting_audio_time_|.
+  // TODO(servolk): Get rid of the lock and replace restarting_audio_ with
+  // std::atomic<bool> when atomics are unbanned in Chromium.
+  base::Lock restarting_audio_lock_;
   bool restarting_audio_ = false;
+  base::TimeDelta restarting_audio_time_ = kNoTimestamp;
+
   bool restarting_video_ = false;
 
   // Flush operations and media track status changes must be serialized to avoid