Make MediaController use low profile system UI

This makes the MediaController iused by the full screen html5 video
view copy the system ui visibility of its owner. Some issues remain.
b/5494143

Change-Id: I6b157226974befbee5ba685d42d1ef72c113664d

Author: marcone

core/java/android/webkit/HTML5VideoFullScreen.java

@@ -150,7 +150,9 @@ public void decideDisplayMode() {
     private void prepareForFullScreen() {
         // So in full screen, we reset the MediaPlayer
         mPlayer.reset();
-        setMediaController(new MediaController(mProxy.getContext()));
+        MediaController mc = new MediaController(mProxy.getContext());
+        mc.setSystemUiVisibility(mLayout.getSystemUiVisibility());
+        setMediaController(mc);
         mPlayer.setScreenOnWhilePlaying(true);
         prepareDataAndDisplayMode(mProxy);
     }