Refactor MSE implementation on Android to simplify the logic and improve the performance

media/base/android/media_source_player.h

Index: media/base/android/media_source_player.h
diff --git a/media/base/android/media_source_player.h b/media/base/android/media_source_player.h
index bd8457ed734ebfeb5ef97dea2cd530154d4cf9e8..7577b35976d90fc466389d9707a423f41501785a 100644
--- a/media/base/android/media_source_player.h
+++ b/media/base/android/media_source_player.h
@@ -100,15 +100,6 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // Handle pending events if all the decoder jobs are not currently decoding.
   void ProcessPendingEvents();
 
-  // Helper method to clear any pending |SURFACE_CHANGE_EVENT_PENDING|
-  // and reset |video_decoder_job_| to null.
-  void ResetVideoDecoderJob();
-  void ResetAudioDecoderJob();
-
-  // Helper methods to configure the decoder jobs.
-  void ConfigureVideoDecoderJob();
-  void ConfigureAudioDecoderJob();
-
   // Flush the decoders and clean up all the data needs to be decoded.
   void ClearDecodingData();
 
@@ -155,9 +146,6 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // since last keyframe. See http://crbug.com/304234.
   void BrowserSeekToCurrentTime();
 
-  // Helper function to set the volume.
-  void SetVolumeInternal();
-
   // Helper function to determine whether a protected surface is needed for
   // video playback.
   bool IsProtectedSurfaceRequired();
@@ -168,6 +156,9 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // resync with audio and starts decoding.
   void OnPrefetchDone();
 
+  // Called when the demuxer config changes.
+  void OnDemuxerConfigsChanged();
+
   // Test-only method to setup hook for the completion of the next decode cycle.
   // This callback state is cleared when it is next run.
   // Prevent usage creep by only calling this from the
@@ -182,10 +173,9 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   enum PendingEventFlags {
     NO_EVENT_PENDING = 0,
     SEEK_EVENT_PENDING = 1 << 0,
-    SURFACE_CHANGE_EVENT_PENDING = 1 << 1,
-    CONFIG_CHANGE_EVENT_PENDING = 1 << 2,
-    PREFETCH_REQUEST_EVENT_PENDING = 1 << 3,
-    PREFETCH_DONE_EVENT_PENDING = 1 << 4,
+    PREFETCH_REQUEST_EVENT_PENDING = 1 << 1,
+    PREFETCH_DONE_EVENT_PENDING = 1 << 2,
+    DECODER_CREATION_EVENT_PENDING = 1 << 3,
   };
 
   static const char* GetEventName(PendingEventFlags event);
@@ -200,20 +190,7 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
 
   // Stats about the media.
   base::TimeDelta duration_;
-  int width_;
-  int height_;
-  AudioCodec audio_codec_;
-  VideoCodec video_codec_;
-  int num_channels_;
-  int sampling_rate_;
-  // TODO(xhwang/qinmin): Add |video_extra_data_|.
-  std::vector<uint8> audio_extra_data_;
-  bool reached_audio_eos_;
-  bool reached_video_eos_;
   bool playing_;
-  bool is_audio_encrypted_;
-  bool is_video_encrypted_;
-  double volume_;
 
   // base::TickClock used by |clock_|.
   base::DefaultTickClock default_tick_clock_;
@@ -230,16 +207,6 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   base::TimeTicks start_time_ticks_;
   base::TimeDelta start_presentation_timestamp_;
 
-  // The surface object currently owned by the player.
-  gfx::ScopedJavaSurface surface_;
-
-  // Track whether or not the player has received any video data since the most
-  // recent of player construction, end of last seek, or receiving and
-  // detecting a |kConfigChanged| access unit from the demuxer.
-  // If no such video data has been received, the next video data begins with
-  // an I-frame. Otherwise, we have no such guarantee.
-  bool next_video_data_is_iframe_;
-
   // Flag that is true if doing a hack browser seek or false if doing a
   // regular seek. Only valid when |SEEK_EVENT_PENDING| is pending.
   // TODO(wolenetz): Instead of doing hack browser seek, replay cached data
@@ -257,9 +224,6 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   scoped_ptr<AudioDecoderJob, MediaDecoderJob::Deleter> audio_decoder_job_;
   scoped_ptr<VideoDecoderJob, MediaDecoderJob::Deleter> video_decoder_job_;
 
-  bool reconfig_audio_decoder_;
-  bool reconfig_video_decoder_;
-
   // Track the most recent preroll target. Decoder re-creation needs this to
   // resume any in-progress preroll.
   base::TimeDelta preroll_timestamp_;
@@ -276,16 +240,19 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // try to start playback again.
   bool is_waiting_for_key_;
 
+  // Indicates whether the player is waiting for audio or video decoder to be
+  // created.
+  // TODO(qinmin): currently only |is_waiting_for_audio_decoder_| is used due to
+  // empty surface. Will remove is_|waiting_for_audio_decoder_| if needed.
+  bool is_waiting_for_audio_decoder_;
+  bool is_waiting_for_video_decoder_;
+
   // Test-only callback for hooking the completion of the next decode cycle.
   base::Closure decode_callback_for_testing_;
 
   // Whether |surface_| is currently used by the player.
   bool is_surface_in_use_;
 
-  // Whether there are pending data requests by the decoder.
-  bool has_pending_audio_data_request_;
-  bool has_pending_video_data_request_;
-
   // Weak pointer passed to media decoder jobs for callbacks.
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<MediaSourcePlayer> weak_factory_;