Fixing bug in MediaStream.java that caused double disposal of track.

webrtc/media/webrtc/webrtcvideoengine2.h

Index: webrtc/media/webrtc/webrtcvideoengine2.h
diff --git a/webrtc/media/webrtc/webrtcvideoengine2.h b/webrtc/media/webrtc/webrtcvideoengine2.h
index 98bad0f0077c33cc584054e4bf2a1f0d353c8345..27eec863edc5fd3863a9a0362fa4518a244b9f29 100644
--- a/webrtc/media/webrtc/webrtcvideoengine2.h
+++ b/webrtc/media/webrtc/webrtcvideoengine2.h
@@ -345,6 +345,8 @@ class WebRtcVideoChannel2 : public VideoMediaChannel,
     VideoEncoderSettings encoder_settings_ GUARDED_BY(lock_);
     AllocatedEncoder allocated_encoder_ GUARDED_BY(lock_);
     Dimensions last_dimensions_ GUARDED_BY(lock_);
+    webrtc::VideoRotation last_rotation_ GUARDED_BY(lock_) =
+        webrtc::kVideoRotation_0;
 
     VideoCapturer* capturer_ GUARDED_BY(lock_);
     bool sending_ GUARDED_BY(lock_);