[Chromecast] Make sure that Stop() stops buffer decryption

chromecast/media/cma/pipeline/av_pipeline_impl.h

 // Copyright 2014 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 CHROMECAST_MEDIA_CMA_PIPELINE_AV_PIPELINE_IMPL_H_
 #define CHROMECAST_MEDIA_CMA_PIPELINE_AV_PIPELINE_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 154 matching lines @@
 
   // Buffer that has been pushed to the device but not processed yet.
   scoped_refptr<DecoderBufferBase> pushed_buffer_;
 
   // CdmContext, if available.
   CastCdmContext* cast_cdm_context_;
   int player_tracker_callback_id_;
 
   base::WeakPtr<AvPipelineImpl> weak_this_;
   base::WeakPtrFactory<AvPipelineImpl> weak_factory_;
+  // Special weak factory used for asynchronous decryption. This allows us to

[alokp, 2016/09/22 17:25:18]

This comment does not seem accurate. IIUC it does not cancel the actual
decryption task but just drops the decryption completion callback. If this is
true, I do not see how this patch helps because we already early-return if
enable_feeding_ is false (which is set in Stop).

+  // cancel pending asynchronous decryption (by invalidating this factory's weak
+  // ptrs) without affecting other bound callbacks.
+  base::WeakPtrFactory<AvPipelineImpl> decrypt_weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AvPipelineImpl);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_PIPELINE_AV_PIPELINE_IMPL_H_