Events refactor in Android session based capturing.

webrtc/api/android/java/src/org/webrtc/CameraVideoCapturer.java

 /*
  *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 103 matching lines @@
         throw new IllegalStateException("Wrong thread");
       }
     }
 
     public void addFrame() {
       checkThread();
       ++frameCount;
     }
 
     public void release() {
-      checkThread();
       surfaceTextureHelper.getHandler().removeCallbacks(cameraObserver);
     }
   }
 }