Pass origin to StartObservingMediaSinks.

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

Index: chrome/browser/ui/webui/media_router/query_result_manager.cc
diff --git a/chrome/browser/ui/webui/media_router/query_result_manager.cc b/chrome/browser/ui/webui/media_router/query_result_manager.cc
index e451fdb3e4971b53f3d2d077d768c3c28eb8a1c4..1aa384bf742f16cf312222177778be65e4cf972c 100644
--- a/chrome/browser/ui/webui/media_router/query_result_manager.cc
+++ b/chrome/browser/ui/webui/media_router/query_result_manager.cc
@@ -29,7 +29,11 @@ class QueryResultManager::CastModeMediaSinksObserver
   ~CastModeMediaSinksObserver() override {}
 
   // MediaSinksObserver
-  void OnSinksReceived(const std::vector<MediaSink>& result) override {
+  void OnSinksReceived(const MediaSource& incomingSource,
+                       const std::vector<MediaSink>& result) override {
+    if (!incomingSource.Equals(source())) {

[mark a. foltz, 2016/03/03 22:58:37]

Similar comment about DCHECK.  It seems like the observer is owned by the frame
which should not change origins?

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

Similar answer.  These will be called.

+      return;
+    }
     latest_sink_ids_.clear();
     for (const MediaSink& sink : result) {
       latest_sink_ids_.push_back(sink.id());