Add histogram for percentage of sent frames that are limited in resolution due to quality.

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 96 matching lines @@
   std::vector<int> last_key_frame_picture_id_;
   std::vector<bool> key_frame_request_;
   std::vector<bool> send_stream_;
   std::vector<int> cpu_speed_;
   std::vector<vpx_image_t> raw_images_;
   std::vector<EncodedImage> encoded_images_;
   std::vector<vpx_codec_ctx_t> encoders_;
   std::vector<vpx_codec_enc_cfg_t> configurations_;
   std::vector<vpx_rational_t> downsampling_factors_;
   QualityScaler quality_scaler_;
+  bool quality_scaler_enabled_;
 };  // end of VP8EncoderImpl class
 
 class VP8DecoderImpl : public VP8Decoder {
  public:
   VP8DecoderImpl();
 
   virtual ~VP8DecoderImpl();
 
   int InitDecode(const VideoCodec* inst, int number_of_cores) override;
 
@@ skipping 31 matching lines @@
   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_