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

webrtc/media/engine/webrtcmediaengine.cc

Index: webrtc/media/engine/webrtcmediaengine.cc
diff --git a/webrtc/media/engine/webrtcmediaengine.cc b/webrtc/media/engine/webrtcmediaengine.cc
index 51a110b88b645aa2678991a9abede312f34463b7..1531be36b5dc1b1c39133be3362dbc82bcc620be 100644
--- a/webrtc/media/engine/webrtcmediaengine.cc
+++ b/webrtc/media/engine/webrtcmediaengine.cc
@@ -168,4 +168,30 @@ std::vector<webrtc::RtpExtension> FilterRtpExtensions(
 
   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