Let audio wait for video to finish prerolling after seek

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 17aa2a8ebdbed4292081768daa86b1a52c05019c..a5873864645376caa6cab4523975b9e79071aff6 100644
--- a/media/base/android/media_source_player.h
+++ b/media/base/android/media_source_player.h
@@ -90,6 +90,8 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
         base::TimeDelta current_presentation_timestamp,
         base::TimeDelta max_presentation_timestamp);
 
+  bool IsPrerollFinished(bool is_audio) const;
+
   // Gets MediaCrypto object from |drm_bridge_|.
   base::android::ScopedJavaLocalRef<jobject> GetMediaCrypto();
 
@@ -107,8 +109,8 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   void DecodeMoreVideo();
 
   // Functions check whether audio/video is present.
-  bool HasVideo();
-  bool HasAudio();
+  bool HasVideo() const;
+  bool HasAudio() const;
 
   // Functions that check whether audio/video stream has reached end of output
   // or are not present in player configuration.
@@ -258,6 +260,9 @@ class MEDIA_EXPORT MediaSourcePlayer : public MediaPlayerAndroid,
   // Test-only callback for hooking the completion of the next decode cycle.
   base::Closure decode_callback_for_testing_;
 
+  // Whether audio or video decoder is in the process of prerolling.
+  bool prerolling_;
+
   // 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_;