WeakPtr destruction order cleanup: media edition.

content/renderer/media/rtc_video_decoder.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_
 #define CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 252 matching lines @@
   std::deque<std::pair<SHMBuffer*, BufferData> > decode_buffers_;
 
   // The id that will be given to the next bitstream buffer. Guarded by |lock_|.
   int32 next_bitstream_buffer_id_;
 
   // A buffer that has an id less than this should be dropped because Reset or
   // 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_|.
+  // on |vda_loop_proxy_|.  NOTE: This must always be last so it's invalidated
+  // before other member variables might be accessed.
   base::WeakPtrFactory<RTCVideoDecoder> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCVideoDecoder);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_