Don't reconfigure the encoder if the video options aren't changing.

webrtc/media/base/mediachannel.h

 /*
  *  Copyright (c) 2004 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 170 matching lines @@
         delay_agnostic_aec == o.delay_agnostic_aec &&
         experimental_ns == o.experimental_ns &&
         adjust_agc_delta == o.adjust_agc_delta &&
         tx_agc_target_dbov == o.tx_agc_target_dbov &&
         tx_agc_digital_compression_gain == o.tx_agc_digital_compression_gain &&
         tx_agc_limiter == o.tx_agc_limiter &&
         recording_sample_rate == o.recording_sample_rate &&
         playout_sample_rate == o.playout_sample_rate &&
         combined_audio_video_bwe == o.combined_audio_video_bwe;
   }
+  bool operator!=(const AudioOptions& o) const { return !(*this == o); }
 
   std::string ToString() const {
     std::ostringstream ost;
     ost << "AudioOptions {";
     ost << ToStringIfSet("aec", echo_cancellation);
     ost << ToStringIfSet("agc", auto_gain_control);
     ost << ToStringIfSet("ns", noise_suppression);
     ost << ToStringIfSet("hf", highpass_filter);
     ost << ToStringIfSet("swap", stereo_swapping);
     ost << ToStringIfSet("audio_jitter_buffer_max_packets",
@@ skipping 71 matching lines @@
     SetFrom(&video_noise_reduction, change.video_noise_reduction);
     SetFrom(&screencast_min_bitrate_kbps, change.screencast_min_bitrate_kbps);
     SetFrom(&is_screencast, change.is_screencast);
   }
 
   bool operator==(const VideoOptions& o) const {
     return video_noise_reduction == o.video_noise_reduction &&
            screencast_min_bitrate_kbps == o.screencast_min_bitrate_kbps &&
            is_screencast == o.is_screencast;
   }
+  bool operator!=(const VideoOptions& o) const { return !(*this == o); }
 
   std::string ToString() const {
     std::ostringstream ost;
     ost << "VideoOptions {";
     ost << ToStringIfSet("noise reduction", video_noise_reduction);
     ost << ToStringIfSet("screencast min bitrate kbps",
                          screencast_min_bitrate_kbps);
     ost << ToStringIfSet("is_screencast ", is_screencast);
     ost << "}";
     return ost.str();
@@ skipping 830 matching lines @@
   // Signal when the media channel is ready to send the stream. Arguments are:
   //     writable(bool)
   sigslot::signal1<bool> SignalReadyToSend;
   // Signal for notifying that the remote side has closed the DataChannel.
   sigslot::signal1<uint32_t> SignalStreamClosedRemotely;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_BASE_MEDIACHANNEL_H_