Pass origin to StartObservingMediaSinks.

chrome/browser/media/router/presentation_media_sinks_observer.cc

Index: chrome/browser/media/router/presentation_media_sinks_observer.cc
diff --git a/chrome/browser/media/router/presentation_media_sinks_observer.cc b/chrome/browser/media/router/presentation_media_sinks_observer.cc
index 809eddde30e78373891078ca3dc1ee6c27106898..21c983abe0c9a85ca9240298d552f290b7e2257a 100644
--- a/chrome/browser/media/router/presentation_media_sinks_observer.cc
+++ b/chrome/browser/media/router/presentation_media_sinks_observer.cc
@@ -26,7 +26,11 @@ PresentationMediaSinksObserver::~PresentationMediaSinksObserver() {
 }
 
 void PresentationMediaSinksObserver::OnSinksReceived(
+    const MediaSource& incomingSource,
     const std::vector<MediaSink>& result) {
+  if (!incomingSource.Equals(source()))

[mark a. foltz, 2016/03/03 22:58:36]

Derek: Should this be a DCHECK()?

[matt.boetger, 2016/03/04 00:22:11]

This method WILL be called with other sources unless we don't want to use the
FOR_EACH_OBSERVER macros.

+    return;
+
   Availability current_availability = result.empty() ? UNAVAILABLE : AVAILABLE;
 
   DVLOG(1) << "PresentationMediaSinksObserver::OnSinksReceived: "