Fixed that RTCCameraPreviewView did not rotate the video on device rotation.

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCCameraPreviewView.h

 /*
  *  Copyright 2015 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 10 matching lines @@
  */
 RTC_EXPORT
 @interface RTCCameraPreviewView : UIView
 
 /** The capture session being rendered in the view. Capture session
  *  is assigned to AVCaptureVideoPreviewLayer async in the same
  *  queue that the AVCaptureSession is started/stopped.
  */
 @property(nonatomic, strong) AVCaptureSession *captureSession;
 
+/** Setting to YES will make sure the video is rotated appropriately
+ *  when the device orientation is changed.
+ */
+@property(nonatomic, assign) BOOL shouldAutoRotate;
+
 @end