[Media Router] Wire through a new MRPM call to update media sinks.

chrome/browser/media/router/mojo/media_router.mojom

Index: chrome/browser/media/router/mojo/media_router.mojom
diff --git a/chrome/browser/media/router/mojo/media_router.mojom b/chrome/browser/media/router/mojo/media_router.mojom
index 683904122489d906d2ffbca2765f76648c824c13..1f25a95ba796172be5f05f7cce0c1b07971f968a 100644
--- a/chrome/browser/media/router/mojo/media_router.mojom
+++ b/chrome/browser/media/router/mojo/media_router.mojom
@@ -286,6 +286,9 @@ interface MediaRouteProvider {
   // Calling this will trigger a firewall prompt on Windows if there is not
   // already a firewall rule for mDNS.
   EnableMdnsDiscovery();
+
+  // Updates media sinks capable of displaying |media_source|.
+  UpdateMediaSinks(string media_source);
 };
 
 // Interface for a service which observes state changes across media