Enable -Winconsistent-missing-override flag.

webrtc/modules/video_coding/codecs/vp8/vp8_impl.h

 /*
  *  Copyright (c) 2012 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.
  *
  * WEBRTC VP8 wrapper interface
@@ skipping 22 matching lines @@
 namespace webrtc {
 
 class TemporalLayers;
 
 class VP8EncoderImpl : public VP8Encoder {
  public:
   VP8EncoderImpl();
 
   virtual ~VP8EncoderImpl();
 
-  virtual int Release();
+  int Release() override;
 
-  virtual int InitEncode(const VideoCodec* codec_settings,
-                         int number_of_cores,
-                         size_t max_payload_size);
+  int InitEncode(const VideoCodec* codec_settings,
+                 int number_of_cores,
+                 size_t max_payload_size) override;
 
-  virtual int Encode(const VideoFrame& input_image,
-                     const CodecSpecificInfo* codec_specific_info,
-                     const std::vector<FrameType>* frame_types);
+  int Encode(const VideoFrame& input_image,
+             const CodecSpecificInfo* codec_specific_info,
+             const std::vector<FrameType>* frame_types) override;
 
-  virtual int RegisterEncodeCompleteCallback(EncodedImageCallback* callback);
+  int RegisterEncodeCompleteCallback(EncodedImageCallback* callback) override;
 
-  virtual int SetChannelParameters(uint32_t packet_loss, int64_t rtt);
+  int SetChannelParameters(uint32_t packet_loss, int64_t rtt) override;
 
-  virtual int SetRates(uint32_t new_bitrate_kbit, uint32_t frame_rate);
+  int SetRates(uint32_t new_bitrate_kbit, uint32_t frame_rate) override;
 
   void OnDroppedFrame() override {}
 
   const char* ImplementationName() const override;
 
  private:
   void SetupTemporalLayers(int num_streams,
                            int num_temporal_layers,
                            const VideoCodec& codec);
 
@@ skipping 94 matching lines @@
   int image_format_;
   vpx_ref_frame_t* ref_frame_;
   int propagation_cnt_;
   int last_frame_width_;
   int last_frame_height_;
   bool key_frame_required_;
 };  // end of VP8DecoderImpl class
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_VP8_IMPL_H_