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

webrtc/media/engine/webrtcvideoengine2.cc

 /*
  *  Copyright (c) 2014 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 1650 matching lines @@
 }
 
 const std::vector<uint32_t>&
 WebRtcVideoChannel2::WebRtcVideoSendStream::GetSsrcs() const {
   return ssrcs_;
 }
 
 void WebRtcVideoChannel2::WebRtcVideoSendStream::SetOptions(
     const VideoOptions& options) {
   rtc::CritScope cs(&lock_);
+
+  VideoOptions old_options = parameters_.options;
+  parameters_.options.SetAll(options);
+  // No need to do anything if the options aren't changing.
+  if (parameters_.options == old_options) {
+    return;
+  }
+
   if (parameters_.codec_settings) {
     LOG(LS_INFO) << "SetCodecAndOptions because of SetOptions; options="
                  << options.ToString();
     SetCodecAndOptions(*parameters_.codec_settings, options);
   } else {
     parameters_.options = options;
   }
 }
 
 webrtc::VideoCodecType CodecTypeFromName(const std::string& name) {
@@ skipping 823 matching lines @@
         rtx_mapping[video_codecs[i].codec.id] !=
             fec_settings.red_payload_type) {
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket