media-internals: Store updates when cannot update.

content/browser/media/media_internals.h

Index: content/browser/media/media_internals.h
diff --git a/content/browser/media/media_internals.h b/content/browser/media/media_internals.h
index 72efdd6b5e93d05d12289f1f5af63dc3989d6993..634d06d844df447d0b8365ab089c82afb5ed79a7 100644
--- a/content/browser/media/media_internals.h
+++ b/content/browser/media/media_internals.h
@@ -50,6 +50,9 @@ class CONTENT_EXPORT MediaInternals
   // thread.
   bool CanUpdate();
 
+  // Replay all saved media events.
+  void SendHistoricalMediaEvents();
+
   // Sends all audio cached data to each registered UpdateCallback.
   void SendAudioStreamData();
 
@@ -86,6 +89,10 @@ class CONTENT_EXPORT MediaInternals
   // thread, but will forward to the IO thread.
   void SendUpdate(const base::string16& update);
 
+  // Saves |update| so that they can be sent when there are UpdateCallback
+  // registered.
+  void SaveUpdate(const base::string16& update);
+
   // Caches |value| under |cache_key| so that future SendAudioLogUpdate() calls
   // will include the current data.  Calls JavaScript |function|(|value|) for
   // each registered UpdateCallback.
@@ -109,6 +116,7 @@ class CONTENT_EXPORT MediaInternals
   // All variables below must be accessed under |lock_|.
   base::Lock lock_;
   bool can_update_;
+  std::list<base::string16> pending_updates_;
   base::DictionaryValue audio_streams_cached_data_;
   int owner_ids_[AUDIO_COMPONENT_MAX];
   scoped_ptr<MediaInternalsUMAHandler> uma_handler_;