Use OnceCallback on Mojo interfaces in //chrome/common/media_router

chrome/browser/media/router/mojo/media_router_mojo_impl.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_MOJO_MEDIA_ROUTER_MOJO_IMPL_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MOJO_MEDIA_ROUTER_MOJO_IMPL_H_
 
 #include <stdint.h>
 
 #include <deque>
@@ skipping 307 matching lines @@
   // of few reasons:
   // (1) The extension crashed and lost unpersisted changes.
   // (2) The extension was updated; temporary data is cleared.
   // (3) The extension has an unforseen bug which causes temporary data to be
   //     persisted incorrectly on suspension.
   void SyncStateToMediaRouteProvider();
 
   // mojom::MediaRouter implementation.
   void RegisterMediaRouteProvider(
       mojom::MediaRouteProviderPtr media_route_provider_ptr,
-      const mojom::MediaRouter::RegisterMediaRouteProviderCallback&
-          callback) override;
+      mojom::MediaRouter::RegisterMediaRouteProviderCallback callback) override;
   void OnIssue(const IssueInfo& issue) override;
   void OnSinksReceived(const std::string& media_source,
                        const std::vector<MediaSinkInternal>& internal_sinks,
                        const std::vector<url::Origin>& origins) override;
   void OnRoutesUpdated(
       const std::vector<MediaRoute>& routes,
       const std::string& media_source,
       const std::vector<std::string>& joinable_route_ids) override;
   void OnSinkAvailabilityUpdated(
       mojom::MediaRouter::SinkAvailability availability) override;
@@ skipping 152 matching lines @@
 #endif
 
   base::WeakPtrFactory<MediaRouterMojoImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterMojoImpl);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MOJO_MEDIA_ROUTER_MOJO_IMPL_H_