Experiment with more aggressive MSE GC on memory pressure

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/memory_pressure_listener.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/optional.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"
@@ skipping 317 matching lines @@
   void SetMemoryReportingState(bool is_memory_reporting_enabled);
   void SetSuspendState(bool is_suspended);
 
   // Called at low frequency to tell external observers how much memory we're
   // using for video playback.  Called by |memory_usage_reporting_timer_|.
   // Memory usage reporting is done in two steps, because |demuxer_| must be
   // accessed on the media thread.
   void ReportMemoryUsage();
   void FinishMemoryUsageReport(int64_t demuxer_memory_usage);
 
+  void OnMemoryPressure(
+      base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
+
   // Called during OnHidden() when we want a suspended player to enter the
   // paused state after some idle timeout.
   void ScheduleIdlePauseTimer();
 
   // Returns |true| before HaveFutureData whenever there has been loading
   // progress and we have not been resumed for at least kLoadingToIdleTimeout
   // since then.
   //
   // This is used to delay suspension long enough for preroll to complete, which
   // is necessay because play() will not be called before HaveFutureData (and
@@ skipping 196 matching lines @@
   // These two are mutually exclusive:
   //   |data_source_| is used for regular resource loads.
   //   |chunk_demuxer_| is used for Media Source resource loads.
   //
   // |demuxer_| will contain the appropriate demuxer based on which resource
   // load strategy we're using.
   std::unique_ptr<MultibufferDataSource> data_source_;
   std::unique_ptr<Demuxer> demuxer_;
   ChunkDemuxer* chunk_demuxer_;
 
+  std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
+
   BufferedDataSourceHostImpl buffered_data_source_host_;
   linked_ptr<UrlIndex> url_index_;
 
   // Video rendering members.
   scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner_;
   VideoFrameCompositor* compositor_;  // Deleted on |compositor_task_runner_|.
   SkCanvasVideoRenderer skcanvas_video_renderer_;
 
   // The compositor layer for displaying the video content when using composited
   // playback.
@@ skipping 87 matching lines @@
 
   std::unique_ptr<base::TickClock> tick_clock_;
 
   // Monitors the player events.
   base::WeakPtr<MediaObserver> observer_;
 
   // The maximum video keyframe distance that allows triggering background
   // playback optimizations.
   base::TimeDelta max_keyframe_distance_to_disable_background_video_;
 
+  // When MSE garbage-collection on memory pressure is enabled, the
+  // |mse_force_gc_on_memory_pressure| controls whether the GC is done
+  // immediately on memory pressure notification or during the next SourceBuffer
+  // append (slower, but more MSE-spec compliant).
+  bool mse_force_gc_on_memory_pressure_;
+
   // 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;
 
   // Pipeline statistics overridden by tests.
   base::Optional<PipelineStatistics> pipeline_statistics_for_test_;
 
   // Pipeline media duration overridden by tests.
   base::Optional<base::TimeDelta> pipeline_media_duration_for_test_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_