Interface for requestSources through UserMediaController/Client.

Source/modules/mediastream/UserMediaController.h

Index: Source/modules/mediastream/UserMediaController.h
diff --git a/Source/modules/mediastream/UserMediaController.h b/Source/modules/mediastream/UserMediaController.h
index 985f0372dd915566d61a162d2115452c1aa23050..c75b829d807078b85213fd14c848029dd496a9e9 100644
--- a/Source/modules/mediastream/UserMediaController.h
+++ b/Source/modules/mediastream/UserMediaController.h
@@ -47,6 +47,8 @@ public:
     void requestMediaDevices(MediaDevicesRequest*);
     void cancelMediaDevicesRequest(MediaDevicesRequest*);
 
+    void requestSources(MediaStreamTrackSourcesRequest*);
+
     static PassOwnPtrWillBeRawPtr<UserMediaController> create(UserMediaClient*);
     static const char* supplementName();
     static UserMediaController* from(LocalFrame* frame) { return static_cast<UserMediaController*>(WillBeHeapSupplement<LocalFrame>::from(frame, supplementName())); }
@@ -80,6 +82,11 @@ inline void UserMediaController::cancelMediaDevicesRequest(MediaDevicesRequest*
     m_client->cancelMediaDevicesRequest(request);
 }
 
+inline void UserMediaController::requestSources(MediaStreamTrackSourcesRequest* request)
+{
+    m_client->requestSources(request);
+}
+
 } // namespace blink
 
 #endif // UserMediaController_h