[Media Router] Add origins to sink query results.

chrome/browser/media/router/media_sinks_observer.h

 // 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.
 
 #ifndef CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINKS_OBSERVER_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINKS_OBSERVER_H_
 
 #include <vector>
 
 #include "base/macros.h"
 #include "chrome/browser/media/router/media_sink.h"
 #include "chrome/browser/media/router/media_source.h"
+#include "url/gurl.h"
 
 namespace media_router {
 
 class MediaRouter;
 
 // Base class for observing when the collection of sinks compatible with
 // a MediaSource has been updated.
 // A MediaSinksObserver implementation can be registered to MediaRouter to
 // receive results. It can then interpret / process the results accordingly.
 // More documentation can be found at
 // docs.google.com/document/d/1RDXdzi2y7lRuL08HAe-qlSJG2DMz2iH3gBzMs0IRR78
 class MediaSinksObserver {
  public:
   // Constructs an observer that will observe for sinks compatible
   // with |source|.

[mark a. foltz, 2016/03/11 01:20:23]

Document meaning of |origin|.

[imcheng, 2016/03/14 21:30:20]

Done.

-  MediaSinksObserver(MediaRouter* router, const MediaSource& source);
+  MediaSinksObserver(MediaRouter* router,
+                     const MediaSource& source,
+                     const GURL& origin);
   virtual ~MediaSinksObserver();
 
   // Registers with MediaRouter to start observing. Must be called before the
   // observer will start receiving updates. Returns |true| if the observer is
   // initialized. This method is no-op if the observer is already initialized.
   bool Init();
 
-  // This function is invoked when the list of sinks compatible
-  // with |source_| has been updated.
-  // Implementations may not perform operations that modify the Media Router's
-  // observer list. In particular, invoking this observer's destructor within
-  // OnSinksReceived will result in undefined behavior.
-  virtual void OnSinksReceived(const std::vector<MediaSink>& sinks) {}
+  // This function is invoked when the list of sinks compatible with |source_|
+  // has been updated. The result also contains the list of valid origins.
+  // If |origins| is empty or contains |origin_|, then |OnSinksReceived(sinks)|
+  // will be invoked with |sinks|. Otherwise, it will be invoked with an empty
+  // list.
+  void OnSinksUpdated(const std::vector<MediaSink>& sinks,
+                      const std::vector<GURL>& origins);
 
   const MediaSource& source() const { return source_; }
 
  private:
+  // This function is invoked from |OnSinksUpdated(sinks, origins)|.
+  // Implementations may not perform operations that modify the Media Router's
+  // observer list. In particular, invoking this observer's destructor within
+  // OnSinksReceived will result in undefined behavior.

[mark a. foltz, 2016/03/11 01:20:23]

This seems like common sense, but maybe it could be enforced by setting a flag
in OnSinksUpdated() and checking it in the dtor?

[imcheng, 2016/03/14 21:30:20]

Done.

+  virtual void OnSinksReceived(const std::vector<MediaSink>& sinks) = 0;

[mark a. foltz, 2016/03/11 01:20:23]

Usually virtual methods that are to be implemented by subclasses are declared
protected: or public:

[imcheng, 2016/03/14 21:30:20]

Done. Moved back to public

+
   const MediaSource source_;
-  MediaRouter* router_;
+  const GURL origin_;
+  MediaRouter* const router_;
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaSinksObserver);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SINKS_OBSERVER_H_