Pass origin to StartObservingMediaSinks.

chrome/browser/media/router/media_router.mojom

Index: chrome/browser/media/router/media_router.mojom
diff --git a/chrome/browser/media/router/media_router.mojom b/chrome/browser/media/router/media_router.mojom
index 9a2f5e7e712f6fa1f0ef0764150f4f385d3a02b2..e349b19e806e7098052212c58eb7a14e9fa88e80 100644
--- a/chrome/browser/media/router/media_router.mojom
+++ b/chrome/browser/media/router/media_router.mojom
@@ -215,10 +215,14 @@ interface MediaRouteProvider {
       => (bool sent);
 
   // Starts querying for sinks capable of displaying |media_source|.
-  StartObservingMediaSinks(string media_source);
+  // |origin| is the origin of the client that is requesting media
+  // sinks. It may be used to verify that |origin| is authorized to
+  // receive sinks for |media_source|.
+  StartObservingMediaSinks(string media_source, string origin);
 
   // Stops querying sinks for |media_source|.
-  StopObservingMediaSinks(string media_source);
+  // |origin| is the origin of the client that started the query.
+  StopObservingMediaSinks(string media_source, string origin);
 
   // Starts reporting the state of active media routes via
   // OnRoutesUpdated() in the context of the |media_source|.  The
@@ -302,7 +306,7 @@ interface MediaRouter {
       (string instance_id);
 
   // Called when the Media Route Manager receives a new list of sinks.
-  OnSinksReceived(string media_source, array<MediaSink> sinks);
+  OnSinksReceived(string media_source, string origin, array<MediaSink> sinks);
 
   // Called when issues are reported for media routes.
   OnIssue(Issue issue);