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 184 matching lines @@
   static const int32 ID_LAST;     // maximum bitstream buffer id
   static const int32 ID_HALF;     // half of the maximum bitstream buffer id
   static const int32 ID_INVALID;  // indicates Reset or Release never occurred
 
   // The hardware video decoder.
   scoped_ptr<media::VideoDecodeAccelerator> vda_;
 
   // 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_|.
   scoped_refptr<base::SingleThreadTaskRunner> vda_task_runner_;
 
   // The texture target used for decoded pictures.
   uint32 decoder_texture_target_;
 
   // Metadata of the buffers that have been sent for decode.
   std::list<BufferData> input_buffer_data_;
@@ skipping 44 matching lines @@
   // decode. The queue owns SHM buffers. Guarded by |lock_|.
   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_|.
+  // 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);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_DECODER_H_