Remove PayloadRouter dependency from ViEEncoder

webrtc/video/encoded_frame_callback_adapter.h

 /*
  *  Copyright (c) 2013 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.
  */
 
 #ifndef WEBRTC_VIDEO_ENCODED_FRAME_CALLBACK_ADAPTER_H_
 #define WEBRTC_VIDEO_ENCODED_FRAME_CALLBACK_ADAPTER_H_
 
 #include "webrtc/common_video/include/frame_callback.h"
 #include "webrtc/modules/video_coding/include/video_codec_interface.h"
 
 namespace webrtc {
 namespace internal {
 
 class EncodedFrameCallbackAdapter : public EncodedImageCallback {
  public:
   explicit EncodedFrameCallbackAdapter(EncodedFrameObserver* observer);
   virtual ~EncodedFrameCallbackAdapter();
 
   virtual int32_t Encoded(const EncodedImage& encodedImage,
                           const CodecSpecificInfo* codecSpecificInfo,
                           const RTPFragmentationHeader* fragmentation);
 
  private:
-  EncodedFrameObserver* observer_;
+  EncodedFrameObserver* const observer_;
 };
 
 }  // namespace internal
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_ENCODED_FRAME_CALLBACK_ADAPTER_H_