Listen to the audio focus event for MSE/EME

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

Index: media/base/android/java/src/org/chromium/media/MediaPlayerListener.java
diff --git a/media/base/android/java/src/org/chromium/media/MediaPlayerListener.java b/media/base/android/java/src/org/chromium/media/MediaPlayerListener.java
index ed37f193c8c196dc9e10e154a6cd5299386f359b..67644b9ae7b2d5268228771f73ad78bb83bd4276 100644
--- a/media/base/android/java/src/org/chromium/media/MediaPlayerListener.java
+++ b/media/base/android/java/src/org/chromium/media/MediaPlayerListener.java
@@ -125,12 +125,14 @@ class MediaPlayerListener implements MediaPlayer.OnPreparedListener,
             Context context, MediaPlayerBridge mediaPlayerBridge) {
         final MediaPlayerListener listener =
                 new MediaPlayerListener(nativeMediaPlayerListener, context);
-        mediaPlayerBridge.setOnBufferingUpdateListener(listener);
-        mediaPlayerBridge.setOnCompletionListener(listener);
-        mediaPlayerBridge.setOnErrorListener(listener);
-        mediaPlayerBridge.setOnPreparedListener(listener);
-        mediaPlayerBridge.setOnSeekCompleteListener(listener);
-        mediaPlayerBridge.setOnVideoSizeChangedListener(listener);
+        if (mediaPlayerBridge != null) {
+            mediaPlayerBridge.setOnBufferingUpdateListener(listener);
+            mediaPlayerBridge.setOnCompletionListener(listener);
+            mediaPlayerBridge.setOnErrorListener(listener);
+            mediaPlayerBridge.setOnPreparedListener(listener);
+            mediaPlayerBridge.setOnSeekCompleteListener(listener);
+            mediaPlayerBridge.setOnVideoSizeChangedListener(listener);
+        }
 
         AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
         am.requestAudioFocus(