Fix an issue that audio and video may run out of sync

media/base/android/java/src/org/chromium/media/MediaCodecBridge.java

Index: media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
diff --git a/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java b/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
index 3f1506113848f1cecd9dd045f6def102e8b2d946..cbfccfd2f80d1b099afa442e62b4d69ab2df9045 100644
--- a/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
+++ b/media/base/android/java/src/org/chromium/media/MediaCodecBridge.java
@@ -280,6 +280,8 @@ class MediaCodecBridge {
         try {
             mFlushed = true;
             if (mAudioTrack != null) {
+                // Need to call pause() here, or otherwise flush() is a no-op.
+                mAudioTrack.pause();
                 mAudioTrack.flush();
             }
             mMediaCodec.flush();
@@ -521,7 +523,7 @@ class MediaCodecBridge {
     }
 
     @CalledByNative
-    private void playOutputBuffer(byte[] buf) {
+    private long playOutputBuffer(byte[] buf) {

[wolenetz, 2014/04/03 18:14:40]

nit: I'm less familiar with Chromium java coding style, but IMO better
documentation of retval would be good to have.

[qinmin, 2014/04/03 21:59:45]

Done. Java doc added.

On 2014/04/03 18:14:40, wolenetz wrote:

         if (mAudioTrack != null) {
             if (AudioTrack.PLAYSTATE_PLAYING != mAudioTrack.getPlayState()) {
                 mAudioTrack.play();
@@ -531,7 +533,17 @@ class MediaCodecBridge {
                 Log.i(TAG, "Failed to send all data to audio output, expected size: " +
                         buf.length + ", actual size: " + size);
             }
+            // TODO(qinmin): Returning the head position allows us to estimate
+            // the current presentation time in native code. However, it is
+            // better to use AudioTrack.getCurrentTimestamp() to get the last
+            // known time when a frame is played. However, we will need to
+            // convert the java nano time to C++ timestamp.
+            // If the stream runs too long, getPlaybackHeadPosition() could
+            // overflow. AudioTimestampHelper in MediaSourcePlayer has the same
+            // issue. See crbug.com/358801.

[wolenetz, 2014/04/03 18:14:40]

nit: s/crbug.com/http:\/\/crbug.com/

[qinmin, 2014/04/03 21:59:45]

Done.

+            return mAudioTrack.getPlaybackHeadPosition();
         }
+        return 0;

[wolenetz, 2014/04/03 18:14:40]

Might we ever call this method when |mAudioTrack| is null? If so, do we
correctly handle a 0 retval in caller (and, in general, do we correctly handle
null mAudioTrack?)

[qinmin, 2014/04/03 21:59:45]

This should never happen in our code. The if statement is just to ensure this
will not be misused in the future. We can also change it to an assert.

On 2014/04/03 18:14:40, wolenetz wrote:

     }
 
     @CalledByNative