Revert "Remove MediaStreamTrack.getSources()."

third_party/WebKit/Source/web/UserMediaClientImpl.cpp

Index: third_party/WebKit/Source/web/UserMediaClientImpl.cpp
diff --git a/third_party/WebKit/Source/web/UserMediaClientImpl.cpp b/third_party/WebKit/Source/web/UserMediaClientImpl.cpp
index 90f266283d051821737ec27a61a7cc48d4199812..185f76125d15109796c550caf84a12a102a84e67 100644
--- a/third_party/WebKit/Source/web/UserMediaClientImpl.cpp
+++ b/third_party/WebKit/Source/web/UserMediaClientImpl.cpp
@@ -30,6 +30,7 @@
 
 #include "web/UserMediaClientImpl.h"
 
+#include "public/platform/WebMediaStreamTrackSourcesRequest.h"
 #include "public/web/WebFrameClient.h"
 #include "public/web/WebMediaDeviceChangeObserver.h"
 #include "public/web/WebMediaDevicesRequest.h"
@@ -58,6 +59,12 @@ void UserMediaClientImpl::requestMediaDevices(MediaDevicesRequest* request) {
     m_client->requestMediaDevices(request);
 }
 
+void UserMediaClientImpl::requestSources(
+    MediaStreamTrackSourcesRequest* request) {
+  if (m_client)
+    m_client->requestSources(request);
+}
+
 void UserMediaClientImpl::setMediaDeviceChangeObserver(MediaDevices* observer) {
   if (m_client)
     m_client->setMediaDeviceChangeObserver(