Provide an API to the example window manager app that supports closing a window.

mojo/services/public/cpp/view_manager/view_manager.h

 // Copyright 2014 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 MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_MANAGER_H_
 #define MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_MANAGER_H_
 
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 10 matching lines @@
 class ViewManagerSynchronizer;
 class ViewTreeNode;
 
 // Approximately encapsulates the View Manager service.
 // Has a synchronizer that keeps a client model in sync with the service.
 // Owned by the connection.
 //
 // TODO: displays
 class ViewManager {
  public:
+  typedef base::Callback<void(ViewManager*, ViewTreeNode*)> RootCallback;
+
   ~ViewManager();
 
   // |ready_callback| is run when the ViewManager connection is established
   // and ready to use.
   static void Create(
       Application* application,
-      const base::Callback<void(ViewManager*)>& root_added_callback);
+      const RootCallback& root_added_callback,
+      const RootCallback& root_removed_callback);
   // Blocks until ViewManager is ready to use.
-  static ViewManager* CreateBlocking(
-      Application* application,
-      const base::Callback<void(ViewManager*)>& root_added_callback);
+  static ViewManager* CreateBlocking(Application* application);
 
   const std::vector<ViewTreeNode*>& roots() { return roots_; }
 
   ViewTreeNode* GetNodeById(TransportNodeId id);
   View* GetViewById(TransportViewId id);
 
  private:
   friend class ViewManagerPrivate;
   typedef std::map<TransportNodeId, ViewTreeNode*> IdToNodeMap;
   typedef std::map<TransportViewId, View*> IdToViewMap;
 
   ViewManager(Application* application,
-              const base::Callback<void(ViewManager*)>& root_added_callback);
+              const RootCallback& root_added_callback,
+              const RootCallback& root_removed_callback);
 
-  base::Callback<void(ViewManager*)> root_added_callback_;
+  RootCallback root_added_callback_;
+  RootCallback root_removed_callback_;
 
   ViewManagerSynchronizer* synchronizer_;
 
   std::vector<ViewTreeNode*> roots_;
 
   IdToNodeMap nodes_;
   IdToViewMap views_;
 
   DISALLOW_COPY_AND_ASSIGN(ViewManager);
 };
 
 }  // namespace view_manager
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_MANAGER_H_