[Remoting Host] Supporting WebRTC VP9 streaming

remoting/protocol/webrtc_video_stream.cc

Index: remoting/protocol/webrtc_video_stream.cc
diff --git a/remoting/protocol/webrtc_video_stream.cc b/remoting/protocol/webrtc_video_stream.cc
index 79a7dceaeff038df1c6854fba7f759e6120de651..72835251cd465d78eef2627df6787903b277e166 100644
--- a/remoting/protocol/webrtc_video_stream.cc
+++ b/remoting/protocol/webrtc_video_stream.cc
@@ -4,6 +4,8 @@
 
 #include "remoting/protocol/webrtc_video_stream.h"
 
+#include <utility>
+
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner_util.h"
@@ -76,8 +78,11 @@ void WebrtcVideoStream::Start(
   encode_task_runner_ = std::move(encode_task_runner);
   capturer_ = std::move(desktop_capturer);
   webrtc_transport_ = webrtc_transport;
-  // TODO(isheriff): make this codec independent
-  encoder_ = WebrtcVideoEncoderVpx::CreateForVP8();
+
+  webrtc_transport_->video_encoder_factory()->RegisterEncoderSelectedCallback(
+      base::Bind(&WebrtcVideoStream::OnEncoderCreated,
+                 weak_factory_.GetWeakPtr()));
+
   capturer_->Start(this);
 
   // Set video stream constraints.
@@ -164,6 +169,8 @@ void WebrtcVideoStream::OnCaptureResult(
     }
   }
 
+  DCHECK(encoder_);
+
   base::PostTaskAndReplyWithResult(
       encode_task_runner_.get(), FROM_HERE,
       base::Bind(&WebrtcVideoStream::EncodeFrame, encoder_.get(),
@@ -261,5 +268,16 @@ void WebrtcVideoStream::OnFrameEncoded(EncodedFrameWithStats frame) {
   }
 }
 
+void WebrtcVideoStream::OnEncoderCreated(webrtc::VideoCodecType codec_type) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (codec_type == webrtc::kVideoCodecVP8) {
+    encoder_ = WebrtcVideoEncoderVpx::CreateForVP8();
+  } else if (codec_type == webrtc::kVideoCodecVP9) {
+    encoder_ = WebrtcVideoEncoderVpx::CreateForVP9();
+  } else {
+    LOG(FATAL) << "Unknown codec type: " << codec_type;
+  }
+}
+
 }  // namespace protocol
 }  // namespace remoting