[Media Router] Add DialMediaSinkService and DeviceDescriptionService

chrome/browser/extensions/api/dial/dial_registry.h

 // Copyright (c) 2012 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_EXTENSIONS_API_DIAL_DIAL_REGISTRY_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_REGISTRY_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 53 matching lines @@
 
   ~DialRegistry() override;
 
   // Called by the DIAL API when event listeners are added or removed. The dial
   // service is started after the first listener is added and stopped after the
   // last listener is removed.
   void OnListenerAdded();
   void OnListenerRemoved();
 
   // This class does not take ownership of observer.
-  void RegisterObserver(Observer* observer);
-  void UnregisterObserver(Observer* observer);
+  virtual void RegisterObserver(Observer* observer);
+  virtual void UnregisterObserver(Observer* observer);
 
   // Called by the DIAL API to try to kickoff a discovery if there is not one
   // already active.
   bool DiscoverNow();
 
   // Returns the URL of the device description for the device identified by
   // |label|, or an empty GURL if no such device exists.
   GURL GetDeviceDescriptionURL(const std::string& label) const;
 
   // Adds a device directly to the registry as if it was discovered.  For tests
@@ skipping 115 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(DialRegistryTest,
                            TestNetworkEventConnectionRestored);
   DISALLOW_COPY_AND_ASSIGN(DialRegistry);
 };
 
 }  // namespace dial
 }  // namespace api
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_REGISTRY_H_