There are reports (not reproducible with appRtcDemo) that outstanding device orientation change event OrientationEventListener.onOrientationChanged can be triggered even after these events are disabled by OrientationEventListener.disable() code. Avoid calling native code in this case since underlying C++ class may have already been deleted. BUG=3564 R=braveyao@webrtc.org Review URL: https://webrtc-codereview.appspot.com/23609004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@7172 4adac7df-926f-26a2-2b94-8c16560cd09d