(Not for review) Dummy C++ side Custom Controls implementation

chrome/browser/ui/webui/media_router/media_router_ui.h

Index: chrome/browser/ui/webui/media_router/media_router_ui.h
diff --git a/chrome/browser/ui/webui/media_router/media_router_ui.h b/chrome/browser/ui/webui/media_router/media_router_ui.h
index c2d1dca6bb142f6f89d2a255b89ec4e9d4ee6c49..d59d9cc1988c2bbfb1a6a719efb3278478f1c1d4 100644
--- a/chrome/browser/ui/webui/media_router/media_router_ui.h
+++ b/chrome/browser/ui/webui/media_router/media_router_ui.h
@@ -13,8 +13,10 @@
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/optional.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/media/router/issue.h"
+#include "chrome/browser/media/router/media_route_status_observer.h"
 #include "chrome/browser/media/router/media_source.h"
 #include "chrome/browser/media/router/presentation_service_delegate_impl.h"
 #include "chrome/browser/ui/webui/constrained_web_dialog_ui.h"
@@ -164,6 +166,20 @@ class MediaRouterUI : public ConstrainedWebDialogUI,
 
   void UpdateMaxDialogHeight(int height);
 
+  // Sends media commands to |route_controller_| if it is set.
+  void PlayRoute();
+  void PauseRoute();
+  void SeekRoute(uint32_t time);
+  void SetRouteMute(bool mute);
+  void SetRouteVolume(float volume);
+
+  // Gets a reference to the MediaRouteController for |route_id| and
+  // instantiates an observer for media status updates for the route.
+  void OnUIDetailsViewOpened(MediaRoute::Id route_id);
+
+  // Resets |route_controller_| and |route_status_observer_|.
+  void OnUIDetailsViewClosed();
+
   void InitForTest(MediaRouter* router,
                    content::WebContents* initiator,
                    MediaRouterWebUIMessageHandler* handler,
@@ -212,6 +228,20 @@ class MediaRouterUI : public ConstrainedWebDialogUI,
     DISALLOW_COPY_AND_ASSIGN(UIMediaRoutesObserver);
   };
 
+  class UIMediaRouteStatusObserver : public MediaRouteStatusObserver {
+   public:
+    UIMediaRouteStatusObserver(MediaRouterWebUIMessageHandler* handler);
+    ~UIMediaRouteStatusObserver() override;
+
+    // MediaRouteStatusObserver
+    void OnMediaRouteStatusUpdated(const MediaStatus& status) override;
+
+   private:
+    MediaRouterWebUIMessageHandler* handler_;
+
+    DISALLOW_COPY_AND_ASSIGN(UIMediaRouteStatusObserver);
+  };
+
   static std::string GetExtensionName(const GURL& url,
                                       extensions::ExtensionRegistry* registry);
 
@@ -291,6 +321,9 @@ class MediaRouterUI : public ConstrainedWebDialogUI,
   // opaque origin ("null") if |initiator_| is not set.
   std::string GetSerializedInitiatorOrigin() const;
 
+  // Returns true if |routes_| contains a route with |route_id|.
+  bool IsValidRouteId(const MediaRoute::Id& route_id) const;
+
   // Owned by the |web_ui| passed in the ctor, and guaranteed to be deleted
   // only after it has deleted |this|.
   MediaRouterWebUIMessageHandler* handler_ = nullptr;
@@ -348,6 +381,16 @@ class MediaRouterUI : public ConstrainedWebDialogUI,
   // been painted and initialized with initial data, this should be cleared.
   base::Time start_time_;
 
+  // The ID of the media route shown in the route details view.
+  base::Optional<MediaRoute::Id> selected_route_;
+
+  // The media controller for |selected_route_|.
+  MediaRouteController* route_controller_ = nullptr;
+
+  // The observer for the media status of |selected_route_| that notifies
+  // |handler_| of updates.
+  std::unique_ptr<UIMediaRouteStatusObserver> route_status_observer_;
+
   // NOTE: Weak pointers must be invalidated before all other member variables.
   // Therefore |weak_factory_| must be placed at the end.
   base::WeakPtrFactory<MediaRouterUI> weak_factory_;