WeakPtr destruction order cleanup: media edition.

media/cast/audio_sender/audio_sender.h

Index: media/cast/audio_sender/audio_sender.h
diff --git a/media/cast/audio_sender/audio_sender.h b/media/cast/audio_sender/audio_sender.h
index 7673b8250faf71d592f4cc6a200ff984f5dd21a5..57ab7e01299c4947b3d171ef5f189543061875c4 100644
--- a/media/cast/audio_sender/audio_sender.h
+++ b/media/cast/audio_sender/audio_sender.h
@@ -68,8 +68,6 @@ class AudioSender : public base::NonThreadSafe,
 
   void InitializeTimers();
 
-  base::WeakPtrFactory<AudioSender> weak_factory_;
-
   scoped_refptr<CastEnvironment> cast_environment_;
   transport::CastTransportSender* const transport_sender_;
   scoped_ptr<AudioEncoder> audio_encoder_;
@@ -79,6 +77,9 @@ class AudioSender : public base::NonThreadSafe,
   bool timers_initialized_;
   CastInitializationStatus cast_initialization_cb_;
 
+  // NOTE: Weak pointers must be invalidated before all other member variables.
+  base::WeakPtrFactory<AudioSender> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioSender);
 };