[Video] Disable bg optimization if avg keyframe distance is >10s

media/blink/webmediaplayer_impl.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 MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_
 #define MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/cancelable_callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread.h"
 #include "base/time/default_tick_clock.h"
+#include "base/time/time.h"
 #include "base/timer/elapsed_timer.h"
 #include "base/timer/timer.h"
 #include "build/build_config.h"
 #include "media/base/media_observer.h"
 #include "media/base/media_tracks.h"
 #include "media/base/pipeline_impl.h"
 #include "media/base/renderer_factory.h"
 #include "media/base/surface_manager.h"
 #include "media/base/text_track.h"
 #include "media/blink/buffered_data_source_host_impl.h"
@@ skipping 581 matching lines @@
   base::TimeTicks last_time_loading_progressed_;
 
   std::unique_ptr<base::TickClock> tick_clock_;
 
   // Monitors the player events.
   base::WeakPtr<MediaObserver> observer_;
 
   // Whether the player is currently in autoplay muted state.
   bool autoplay_muted_ = false;
 
+  // The maximum video keyframe distance that allows triggering background
+  // playback optimizations.
+  // 10 seconds by default but can be overridden by a Finch experiment.
+  base::TimeDelta max_keyframe_distance_for_fast_decode_ =

[DaleCurtis, 2017/01/11 01:14:51]

Replace fast_decode_ terminology like before.

[whywhat, 2017/01/11 17:17:33]

Done.

+      base::TimeDelta::FromSeconds(10);
+
   // Whether disabled the video track as an optimization.
   bool video_track_disabled_ = false;
 
   // Whether the pipeline is being resumed at the moment.
   bool is_pipeline_resuming_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_