Avoid flooding main thread by caching state on media thread.

media/base/pipeline_impl.h

 // Copyright (c) 2016 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 MEDIA_BASE_PIPELINE_IMPL_H_
 #define MEDIA_BASE_PIPELINE_IMPL_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 110 matching lines @@
   void OnError(PipelineStatus error);
   void OnEnded();
   void OnMetadata(PipelineMetadata metadata);
   void OnBufferingStateChange(BufferingState state);
   void OnDurationChange(base::TimeDelta duration);
   void OnAddTextTrack(const TextTrackConfig& config,
                       const AddTextTrackDoneCB& done_cb);
   void OnWaitingForDecryptionKey();
   void OnVideoNaturalSizeChange(const gfx::Size& size);
   void OnVideoOpacityChange(bool opaque);
-  void OnBufferedTimeRangesChange(const Ranges<base::TimeDelta>& ranges);
-  void OnStatisticsUpdate(const PipelineStatistics& stats);
 
   // Task completion callbacks from RendererWrapper.
   void OnSeekDone(base::TimeDelta start_time);
   void OnSuspendDone(base::TimeDelta suspend_time);
 
   // Parameters passed in the constructor.
   const scoped_refptr<base::SingleThreadTaskRunner> media_task_runner_;
   const scoped_refptr<MediaLog> media_log_;
 
   // Pipeline client. Valid only while the pipeline is running.
@@ skipping 11 matching lines @@
   // Current playback rate (>= 0.0). This value is set immediately via
   // SetPlaybackRate() and a task is dispatched on the task runner to notify
   // the filters.
   double playback_rate_;
 
   // Current volume level (from 0.0f to 1.0f). This value is set immediately
   // via SetVolume() and a task is dispatched on the task runner to notify the
   // filters.
   float volume_;
 
-  // Amount of available buffered data as reported by Demuxer.
-  Ranges<base::TimeDelta> buffered_time_ranges_;
-
   // Current duration as reported by Demuxer.
   base::TimeDelta duration_;
 
-  // True when OnBufferedTimeRangesChange() has been called more recently than
-  // DidLoadingProgress().
-  bool did_loading_progress_;
-
-  // Accumulated statistics reported by the renderer.
-  PipelineStatistics statistics_;
-
   base::ThreadChecker thread_checker_;
   base::WeakPtrFactory<PipelineImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PipelineImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_PIPELINE_IMPL_H_