Determine the audible state in MediaSourcePlayer

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 874e61add84c22ed95a1da86f47843da73991716..6db908ac3d9b9cb1048a27be9745e52bcfc3a076 100644
--- a/media/base/android/media_source_player.h
+++ b/media/base/android/media_source_player.h
@@ -69,7 +69,10 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   void OnDemuxerSeekDone(base::TimeDelta actual_browser_seek_time) override;
   void OnDemuxerDurationChanged(base::TimeDelta duration) override;
 
- private:
+  // Sets the idle period after which the audible state is considered gone.
+  void SetAudibleStateIdlePeriod(base::TimeDelta duration);
+
+private:
   friend class MediaSourcePlayerTest;
 
   // Update the current timestamp.
@@ -168,6 +171,9 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // Called when the CDM is detached.
   void OnCdmUnset();
 
+  // Set the status that the audio is currently playing
+  void UpdateAudibleStatus();
+
   // 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
@@ -245,6 +251,16 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // elapses.
   base::CancelableClosure decoder_starvation_callback_;
 
+  // A cancelable task that is reposted every time we enqueue an audio frame.
+  // It arrived when the stream of frames interrupted, telling there is
+  // no audible audio any more.
+  base::CancelableClosure audible_audio_stopped_callback_;
+
+  // The delay for audible_audio_stopped_callback_.
+  // If a new audio frame arrives after this delay,
+  // we will report non-audible state.
+  base::TimeDelta audible_state_idle_period_;
+
   MediaDrmBridge* drm_bridge_;
   int cdm_registration_id_;