RTCRtpReceiver.getContributingSources() added.

third_party/WebKit/public/platform/WebRTCRtpReceiver.h

Index: third_party/WebKit/public/platform/WebRTCRtpReceiver.h
diff --git a/third_party/WebKit/public/platform/WebRTCRtpReceiver.h b/third_party/WebKit/public/platform/WebRTCRtpReceiver.h
index 36c4da8fb43620628b500c6319d3837a76411c44..302b09b7306cd4c077db7ef3192e3a8b9c815680 100644
--- a/third_party/WebKit/public/platform/WebRTCRtpReceiver.h
+++ b/third_party/WebKit/public/platform/WebRTCRtpReceiver.h
@@ -7,10 +7,12 @@
 
 #include "WebCommon.h"
 #include "WebString.h"
+#include "WebVector.h"
 
 namespace blink {
 
 class WebMediaStreamTrack;
+class WebRTCRtpContributingSource;
 
 // Implementations of this interface keep the corresponding WebRTC-layer
 // receiver alive through reference counting. Multiple |WebRTCRtpReceiver|s
@@ -24,6 +26,8 @@ class BLINK_PLATFORM_EXPORT WebRTCRtpReceiver {
   // the same |id|.
   virtual uintptr_t id() const = 0;
   virtual const WebMediaStreamTrack& track() const = 0;
+  virtual WebVector<std::unique_ptr<WebRTCRtpContributingSource>>
+  getSources() = 0;
 };
 
 }  // namespace blink