Get rid of unnecessary cast of FlexfecReceiveStreamImpl to FlexfecReceiveStream

webrtc/media/engine/fakewebrtccall.h

 /*
  *  Copyright (c) 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 199 matching lines @@
   webrtc::VideoReceiveStream::Config config_;
   bool receiving_;
   webrtc::VideoReceiveStream::Stats stats_;
 };
 
 class FakeFlexfecReceiveStream final : public webrtc::FlexfecReceiveStream {
  public:
   explicit FakeFlexfecReceiveStream(
       const webrtc::FlexfecReceiveStream::Config& config);
 
-  const webrtc::FlexfecReceiveStream::Config& GetConfig() const;
+  const webrtc::FlexfecReceiveStream::Config& GetConfig() const override;
 
  private:
   // webrtc::FlexfecReceiveStream implementation.
   void Start() override;
   void Stop() override;
 
   webrtc::FlexfecReceiveStream::Stats GetStats() const override;
 
   webrtc::FlexfecReceiveStream::Config config_;
   bool receiving_;
@@ skipping 89 matching lines @@
 
   int num_created_send_streams_;
   int num_created_receive_streams_;
 
   int audio_transport_overhead_;
   int video_transport_overhead_;
 };
 
 }  // namespace cricket
 #endif  // WEBRTC_MEDIA_ENGINE_FAKEWEBRTCCALL_H_