Adapt encoder behavior to target bitrate

remoting/protocol/webrtc_video_encoder.cc

Index: remoting/protocol/webrtc_video_encoder.cc
diff --git a/remoting/protocol/webrtc_video_encoder.cc b/remoting/protocol/webrtc_video_encoder.cc
index 39c27ec22d4830c87a3ddf9865d4842b26268470..2bb668a599c7c7fbd4461675141b630f3ac82c49 100644
--- a/remoting/protocol/webrtc_video_encoder.cc
+++ b/remoting/protocol/webrtc_video_encoder.cc
@@ -44,7 +44,6 @@ int32_t WebRtcVideoEncoder::InitEncode(const webrtc::VideoCodec* codec_settings,
       }
     }
   }
-  target_bitrate_ = codec_settings->startBitrate;
   state_ = kInitialized;
   return WEBRTC_VIDEO_CODEC_OK;
 }
@@ -84,7 +83,8 @@ int32_t WebRtcVideoEncoder::SetChannelParameters(uint32_t packet_loss,
 int32_t WebRtcVideoEncoder::SetRates(uint32_t bitrate, uint32_t framerate) {
   VLOG(1) << "WebRtcVideoEncoder::SetRates bitrate:framerate " << bitrate << ":"
           << framerate;
-  target_bitrate_ = bitrate;
+  if (!target_bitrate_cb_.is_null())
+    target_bitrate_cb_.Run(bitrate);
   // framerate is not expected to be valid given we never report captured
   // frames
   return WEBRTC_VIDEO_CODEC_OK;
@@ -144,6 +144,12 @@ void WebRtcVideoEncoder::SetKeyFrameRequestCallback(
   key_frame_request_ = key_frame_request;
 }
 
+void WebRtcVideoEncoder::SetTargetBitrateCallback(
+    const TargetBitrateCallback& target_bitrate_cb) {
+  base::AutoLock lock(lock_);
+  target_bitrate_cb_ = target_bitrate_cb;
+}
+
 WebRtcVideoEncoderFactory::WebRtcVideoEncoderFactory() {
   // TODO(isheriff): These do not really affect anything internally
   // in webrtc.
@@ -162,6 +168,7 @@ webrtc::VideoEncoder* WebRtcVideoEncoderFactory::CreateVideoEncoder(
   WebRtcVideoEncoder* encoder = new WebRtcVideoEncoder(type);
   base::AutoLock lock(lock_);
   encoder->SetKeyFrameRequestCallback(key_frame_request_);
+  encoder->SetTargetBitrateCallback(target_bitrate_cb_);
   VLOG(1) << "Created " << encoder;
   encoders_.push_back(base::WrapUnique(encoder));
   return encoder;
@@ -218,4 +225,17 @@ void WebRtcVideoEncoderFactory::SetKeyFrameRequestCallback(
                << encoders_.size();
   }
 }
+
+void WebRtcVideoEncoderFactory::SetTargetBitrateCallback(
+    const TargetBitrateCallback& target_bitrate_cb) {
+  base::AutoLock lock(lock_);
+  target_bitrate_cb_ = target_bitrate_cb;
+  if (encoders_.size() == 1) {
+    encoders_.front()->SetTargetBitrateCallback(target_bitrate_cb);
+  } else {
+    LOG(ERROR) << "Dropping target bitrate request callback with unexpected"
+                  " number of encoders"
+               << encoders_.size();
+  }
+}
 }  // namespace remoting