Pass origin to StartObservingMediaSinks.

chrome/browser/ui/webui/media_router/media_router_ui.cc

Index: chrome/browser/ui/webui/media_router/media_router_ui.cc
diff --git a/chrome/browser/ui/webui/media_router/media_router_ui.cc b/chrome/browser/ui/webui/media_router/media_router_ui.cc
index 9ceaded12d2a37d7dadf2aecba9bd26eef842c82..9accd33d303fcdf698c81d0fdabce2023aefdf6b 100644
--- a/chrome/browser/ui/webui/media_router/media_router_ui.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_ui.cc
@@ -247,14 +247,20 @@ void MediaRouterUI::InitCommon(content::WebContents* initiator) {
   query_result_manager_.reset(new QueryResultManager(router_));
   query_result_manager_->AddObserver(this);
 
+  // Requesting route for mirroring. Use a placeholder URL as origin.
+  GURL origin = GURL(chrome::kChromeUIMediaRouterURL);
+  DCHECK(origin.is_valid());
+
   // These modes are always available.
   query_result_manager_->StartSinksQuery(MediaCastMode::DESKTOP_MIRROR,
-                                         MediaSourceForDesktop());
+                                         MediaSourceForDesktop(),
+                                         origin);
   initiator_ = initiator;
   MediaSource mirroring_source(
       MediaSourceForTab(SessionTabHelper::IdForTab(initiator)));
   query_result_manager_->StartSinksQuery(MediaCastMode::TAB_MIRROR,
-                                         mirroring_source);
+                                         mirroring_source,
+                                         origin);
   UpdateCastModes();
 }
 
@@ -262,7 +268,8 @@ void MediaRouterUI::OnDefaultPresentationChanged(
     const PresentationRequest& presentation_request) {
   MediaSource source = presentation_request.GetMediaSource();
   presentation_request_.reset(new PresentationRequest(presentation_request));
-  query_result_manager_->StartSinksQuery(MediaCastMode::DEFAULT, source);
+  query_result_manager_->StartSinksQuery(MediaCastMode::DEFAULT,
+                                         source, GetFrameURL());
   // Register for MediaRoute updates.
   routes_observer_.reset(new UIMediaRoutesObserver(
       router_, source.id(),