[Media Router] Sync state when MR extension is (re)connected to MR.

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 147 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoExtensionTest,
                            DeferredBindingAndSuspension);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoExtensionTest,
                            DrainPendingRequestQueue);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoExtensionTest,
                            DropOldestPendingRequest);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoExtensionTest,
                            AttemptedWakeupTooManyTimes);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoExtensionTest,
                            WakeupFailedDrainsQueue);
+  FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoExtensionTest,
+                           SyncStateToMediaRouteProvider);
 
   // The max number of pending requests allowed. When number of pending requests
   // exceeds this number, the oldest request will be dropped.
   static const int kMaxPendingRequests = 30;
 
   // Max consecutive attempts to wake up the component extension before
   // giving up and draining the pending request queue.
   static const int kMaxWakeupAttemptCount = 3;
 
   // Represents a query to the MRPM for media sinks and holds observers for the
@@ skipping 14 matching lines @@
 
    private:
     DISALLOW_COPY_AND_ASSIGN(MediaSinksQuery);
   };
 
   struct MediaRoutesQuery {
    public:
     MediaRoutesQuery();
     ~MediaRoutesQuery();
 
-    // True if the query has been sent to the MRPM.  False otherwise.
-    bool is_active = false;
-
     // Cached list of routes and joinable route IDs for the query.
     base::Optional<std::vector<MediaRoute>> cached_route_list;
     std::vector<std::string> joinable_route_ids;
 
     base::ObserverList<MediaRoutesObserver> observers;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(MediaRoutesQuery);
   };
 
@@ skipping 87 matching lines @@
       const MediaRoute::Id& route_id,
       mojom::MediaControllerRequest mojo_media_controller_request,
       mojom::MediaStatusObserverPtr mojo_observer);
 
   void DoProvideSinks(const std::string& provider_name,
                       const std::vector<MediaSinkInternal>& sinks);
 
   // Error handler callback for |binding_| and |media_route_provider_|.
   void OnConnectionError();
 
+  // Issues 0+ calls to |media_route_provider_| to ensure its state is in sync
+  // with MediaRouter on a best-effort basis. This method can be only called if
+  // |media_route_provider_| is a valid handle.

[mark a. foltz, 2017/05/03 17:37:08]

Logically, this should be kicked off in RegisterMediaRouteProvider().  Won't the
handle be guaranteed to be valid then?

[imcheng, 2017/05/03 18:22:41]

Correct. In other words, having a valid MRP handle is a precondition of this
method.

+  // The extension might have become out of sync with MediaRouter due to one
+  // 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 EnsureMediaRouteProviderStateSynced();

[mark a. foltz, 2017/05/03 17:37:08]

Can this be a verb, i.e. SyncToMediaRouteProvider() ?

[imcheng, 2017/05/03 18:22:41]

Renamed to SyncStateToMediaRouteProvider.

+
   // mojom::MediaRouter implementation.
   void RegisterMediaRouteProvider(
       mojom::MediaRouteProviderPtr media_route_provider_ptr,
       const 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(
@@ skipping 149 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_