WeakPtr destruction order cleanup: media edition.

content/renderer/media/rtc_video_decoder.h

Index: content/renderer/media/rtc_video_decoder.h
diff --git a/content/renderer/media/rtc_video_decoder.h b/content/renderer/media/rtc_video_decoder.h
index 007f9b0490a3bf38d992ee583eccf91c9f2d7c6f..f0eb4bdd66a7b7f9fe943e69827f91770fe81ca7 100644
--- a/content/renderer/media/rtc_video_decoder.h
+++ b/content/renderer/media/rtc_video_decoder.h
@@ -202,9 +202,6 @@ class CONTENT_EXPORT RTCVideoDecoder
   // The size of the incoming video frames.
   gfx::Size frame_size_;
 
-  // Weak pointer to this, which can be dereferenced only on |vda_task_runner_|.
-  base::WeakPtr<RTCVideoDecoder> weak_this_;
-
   scoped_refptr<media::GpuVideoAcceleratorFactories> factories_;
 
   // The task runner to run callbacks on. This is from |factories_|.
@@ -269,8 +266,8 @@ class CONTENT_EXPORT RTCVideoDecoder
   // Release has been called. Guarded by |lock_|.
   int32 reset_bitstream_buffer_id_;
 
-  // Factory used to populate |weak_this_|. Must be destroyed, or invalidated,
-  // on |vda_loop_proxy_|.
+  // Must be destroyed, or invalidated, on |vda_loop_proxy_|
+  // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<RTCVideoDecoder> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCVideoDecoder);