RTCRtpReceiver.getContributingSources() added.

content/renderer/media/webrtc/rtc_rtp_receiver.cc

Index: content/renderer/media/webrtc/rtc_rtp_receiver.cc
diff --git a/content/renderer/media/webrtc/rtc_rtp_receiver.cc b/content/renderer/media/webrtc/rtc_rtp_receiver.cc
index f558e74d5a56b392eae6fed584beb83448ea7f0c..c23a1349d4810722aa72caea012080fb2c71ca89 100644
--- a/content/renderer/media/webrtc/rtc_rtp_receiver.cc
+++ b/content/renderer/media/webrtc/rtc_rtp_receiver.cc
@@ -5,6 +5,8 @@
 #include "content/renderer/media/webrtc/rtc_rtp_receiver.h"
 
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "content/renderer/media/webrtc/rtc_rtp_contributing_source.h"
 #include "third_party/webrtc/base/scoped_ref_ptr.h"
 
 namespace content {
@@ -43,6 +45,17 @@ const blink::WebMediaStreamTrack& RTCRtpReceiver::Track() const {
   return web_track_;
 }
 
+blink::WebVector<std::unique_ptr<blink::WebRTCRtpContributingSource>>
+RTCRtpReceiver::GetSources() {
+  auto webrtc_sources = webrtc_rtp_receiver_->GetSources();
+  blink::WebVector<std::unique_ptr<blink::WebRTCRtpContributingSource>> sources(
+      webrtc_sources.size());
+  for (size_t i = 0; i < webrtc_sources.size(); ++i) {
+    sources[i] = base::MakeUnique<RTCRtpContributingSource>(webrtc_sources[i]);
+  }
+  return sources;
+}
+
 const webrtc::MediaStreamTrackInterface& RTCRtpReceiver::webrtc_track() const {
   const webrtc::MediaStreamTrackInterface* webrtc_track =
       webrtc_rtp_receiver_->track();