Pass origin to StartObservingMediaSinks.

chrome/browser/media/router/media_sinks_observer.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/media/router/media_sinks_observer.h"
 
 #include "base/logging.h"
 #include "chrome/browser/media/router/media_router.h"
 
 namespace media_router {
 
 MediaSinksObserver::MediaSinksObserver(MediaRouter* router,
-                                       const MediaSource& source)
-    : source_(source), router_(router), initialized_(false) {
+                                       const MediaSource& source,
+                                       const GURL& origin)
+    : source_(source), router_(router), initialized_(false), origin_(origin) {
   DCHECK(router_);
 }
 
 MediaSinksObserver::~MediaSinksObserver() {
   if (initialized_)
     router_->UnregisterMediaSinksObserver(this);
 }
 
 bool MediaSinksObserver::Init() {
   if (initialized_)
     return true;
 
   initialized_ = router_->RegisterMediaSinksObserver(this);
   return initialized_;
 }
 
 }  // namespace media_router