Convert WMPI state management to level-triggered.

media/blink/webmediaplayer_impl.h

Index: media/blink/webmediaplayer_impl.h
diff --git a/media/blink/webmediaplayer_impl.h b/media/blink/webmediaplayer_impl.h
index fac56ed155e12fb134fabf55742bf12a0e55f46c..eec64fe7a55c1609aaee651ab10b1875210ce977 100644
--- a/media/blink/webmediaplayer_impl.h
+++ b/media/blink/webmediaplayer_impl.h
@@ -196,8 +196,16 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   void OnPipelineSeeked(bool time_updated);
 
  private:
+  // Play states that are meaningful to |delegate_|.
+  // TODO(sandersd): This should move into WebMediaPlayerDelegate.

[DaleCurtis, 2016/03/25 23:21:23]

Why not do it in this patch set then?

[sandersd (OOO until July 31), 2016/03/25 23:42:42]

The easy answer is that the Play state has additional metadata to be passed, and
so the correct API is not clear. (I suspect that the TODO for duration change
will inform that choice though.)

There is also a related refactoring for the other direction:
OnHidden()/OnShown()/OnSuspendRequested() should be merged into a similar set of
'suspend reasons'. There is a different problem there: idle and background can
be true at the same time, so the best API isn't obvious either.

+  enum class PlayState {
+    GONE,
+    PLAYING,
+    PAUSED,
+    ENDED,
+  };
+
   void OnPipelineSuspended();
-  void OnPipelineResumed();
   void OnPipelineEnded();
   void OnPipelineError(PipelineStatus error);
   void OnPipelineMetadata(PipelineMetadata metadata);
@@ -274,10 +282,16 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   // Called when a CDM has been attached to the |pipeline_|.
   void OnCdmAttached(bool success);
 
-  // Notifies |delegate_| that playback has started or was paused; also starts
-  // or stops the memory usage reporting timer respectively.
-  void NotifyPlaybackStarted();
-  void NotifyPlaybackPaused();
+  // Inspectes the current playback state and:
+  //   - notifies |delegate_|,
+  //   - toggles the memory usage reporting timer, and
+  //   - toggles suspend/resume as necessary.
+  // This method should be called any time its dependent variables are changed.
+  void UpdatePlayState();
+
+  // Internal to UpdatePlayState()
+  // TODO(sandersd): Move this into |delegate_|.
+  void UpdatePlayState_SetPlayState(PlayState new_state);
 
   // Called at low frequency to tell external observers how much memory we're
   // using for video playback.  Called by |memory_usage_reporting_timer_|.
@@ -286,14 +300,21 @@ class MEDIA_BLINK_EXPORT WebMediaPlayerImpl
   void ReportMemoryUsage();
   void FinishMemoryUsageReport(int64_t demuxer_memory_usage);
 
-  // Indicates if automatic resumption of a suspended playback is allowed.
-  bool IsAutomaticResumeAllowed();
-
   blink::WebLocalFrame* frame_;
 
+  // The play state last reported to |delegate_|.
+  PlayState play_state_;
+
+  // Set when OnSuspendRequested() is called with |must_suspend| unset.
+  bool idle_suspend_;
+
+  // Set when OnSuspendRequested() is called with |must_suspend| set.
+  bool must_suspend_;
+
   // TODO(hclam): get rid of these members and read from the pipeline directly.
   blink::WebMediaPlayer::NetworkState network_state_;
   blink::WebMediaPlayer::ReadyState ready_state_;
+  blink::WebMediaPlayer::ReadyState highest_ready_state_;
 
   // Preload state for when |data_source_| is created after setPreload().
   BufferedDataSource::Preload preload_;