Fix AudioPump to pause the stream when the network is congested.

remoting/codec/audio_encoder_opus.cc

Index: remoting/codec/audio_encoder_opus.cc
diff --git a/remoting/codec/audio_encoder_opus.cc b/remoting/codec/audio_encoder_opus.cc
index b2a9b5eafe431463908e1a1bf85215e36a5dce2a..ab7582b8a900217f69273413eb93aa249a16a1c1 100644
--- a/remoting/codec/audio_encoder_opus.cc
+++ b/remoting/codec/audio_encoder_opus.cc
@@ -134,6 +134,10 @@ void AudioEncoderOpus::FetchBytesToResample(int resampler_frame_delay,
   DCHECK_LE(resampling_data_pos_, static_cast<int>(resampling_data_size_));
 }
 
+int AudioEncoderOpus::GetBitrate() {
+  return kOutputBitrateBps;
+}
+
 scoped_ptr<AudioPacket> AudioEncoderOpus::Encode(
     scoped_ptr<AudioPacket> packet) {
   DCHECK_EQ(AudioPacket::ENCODING_RAW, packet->encoding());