Convert ViewProviderApp and ContentViewerApp to implement ApplicationImplBase instead of Applicatio…

mojo/ui/content_viewer_app.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 MOJO_UI_CONTENT_VIEWER_APP_H_
 #define MOJO_UI_CONTENT_VIEWER_APP_H_
 
 #include "mojo/common/strong_binding_set.h"
+#include "mojo/public/cpp/application/application_impl_base.h"
+#include "mojo/public/cpp/system/macros.h"
 #include "mojo/services/content_handler/interfaces/content_handler.mojom.h"
-#include "mojo/ui/view_provider_app.h"
 
 namespace mojo {
+
+class ServiceProviderImpl;
+
 namespace ui {
 
+class ViewProviderApp;
+
 // A simple ContentHandler application implementation for rendering
 // content as Views.  Subclasses must provide a function to create
 // the view provider application on demand.
 //
 // TODO(jeffbrown): Support creating the view provider application in a
 // separate thread if desired (often not the case).  This is one reason
 // we are not using the ContentHandlerFactory here.
-class ContentViewerApp : public ApplicationDelegate {
+class ContentViewerApp : public ApplicationImplBase {
  public:
   ContentViewerApp();
   ~ContentViewerApp() override;
 
-  ApplicationImpl* app_impl() { return app_impl_; }
-
-  // |ApplicationDelegate|:
-  void Initialize(ApplicationImpl* app) override;
-  bool ConfigureIncomingConnection(
-      ServiceProviderImpl* service_provider_impl) override;
+  // |ApplicationImplBase|:
+  void OnInitialize() override;
+  bool OnAcceptConnection(ServiceProviderImpl* service_provider_impl) override;
 
   // Called to create the view provider application to view the content.
   //
   // This method may be called multiple times to load different content
   // into separate view providers.  The view provider implementation should
   // cache the loaded content in case it is asked to create multiple instances
   // of the view since the response can only be consumed once.
   //
   // The |content_handler_url| is the connection URL of the content handler
   // request.
   // The |response| carries the data retrieved by the content handler.
   //
-  // Returns the view provider application delegate to view the content,
-  // or nullptr if the content could not be loaded.
+  // Returns the view provider application to view the content, or nullptr if
+  // the content could not be loaded.
+  //
+  // TODO(vtl): This interface is a bit broken. (What's the ownership of the
+  // returned ViewProviderApp implementation?) See my TODO in the implementation
+  // of StartViewer().
   virtual ViewProviderApp* LoadContent(const std::string& content_handler_url,
                                        URLResponsePtr response) = 0;
 
  private:
   class DelegatingContentHandler;
 
   void StartViewer(const std::string& content_handler_url,
                    InterfaceRequest<Application> application_request,
                    URLResponsePtr response);
 
-  ApplicationImpl* app_impl_ = nullptr;
   StrongBindingSet<ContentHandler> bindings_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(ContentViewerApp);
 };
 
 }  // namespace ui
 }  // namespace mojo
 
 #endif  // MOJO_UI_CONTENT_VIEWER_APP_H_