Wire up x-google-{min,start,max}-bitrate to WebRtcVoiceMediaChannel.

webrtc/media/engine/webrtcmediaengine.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 150 matching lines @@
     // Keep just the highest priority extension of any in the following list.
     static const char* kBweExtensionPriorities[] = {
         webrtc::RtpExtension::kTransportSequenceNumberUri,
         webrtc::RtpExtension::kAbsSendTimeUri,
         webrtc::RtpExtension::kTimestampOffsetUri};
     DiscardRedundantExtensions(&result, kBweExtensionPriorities);
   }
 
   return result;
 }
+
+webrtc::Call::Config::BitrateConfig GetBitrateConfigForCodec(
+    const Codec& codec) {
+  webrtc::Call::Config::BitrateConfig config;
+  int bitrate_kbps = 0;
+  if (codec.GetParam(kCodecParamMinBitrate, &bitrate_kbps) &&
+      bitrate_kbps > 0) {
+    config.min_bitrate_bps = bitrate_kbps * 1000;
+  } else {
+    config.min_bitrate_bps = 0;
+  }
+  if (codec.GetParam(kCodecParamStartBitrate, &bitrate_kbps) &&
+      bitrate_kbps > 0) {
+    config.start_bitrate_bps = bitrate_kbps * 1000;
+  } else {
+    // Do not reconfigure start bitrate unless it's specified and positive.
+    config.start_bitrate_bps = -1;
+  }
+  if (codec.GetParam(kCodecParamMaxBitrate, &bitrate_kbps) &&
+      bitrate_kbps > 0) {
+    config.max_bitrate_bps = bitrate_kbps * 1000;
+  } else {
+    config.max_bitrate_bps = -1;
+  }
+  return config;
+}
 }  // namespace cricket