Standardize usage of virtual/override/final in mojo/

mojo/apps/js/content_handler_impl.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_APPS_JS_CONTENT_HANDLER_IMPL_H_
 #define MOJO_APPS_JS_CONTENT_HANDLER_IMPL_H_
 
 #include "mojo/services/public/interfaces/content_handler/content_handler.mojom.h"
 
 namespace mojo {
 namespace apps {
 
 class ApplicationDelegateImpl;
 
 // Starts a new JSApp for each OnConnect call().
 class ContentHandlerImpl : public InterfaceImpl<ContentHandler> {
  public:
   ContentHandlerImpl(ApplicationDelegateImpl* app_delegate_impl);
 
  private:
-  virtual ~ContentHandlerImpl();
-  virtual void OnConnect(
-      const mojo::String& url,
-      URLResponsePtr content,
-      InterfaceRequest<ServiceProvider> service_provider) override;
+  ~ContentHandlerImpl() override;
+  void OnConnect(const mojo::String& url,
+                 URLResponsePtr content,
+                 InterfaceRequest<ServiceProvider> service_provider) override;
 
   ApplicationDelegateImpl* app_delegate_impl_;
 };
 
 }  // namespace apps
 }  // namespace mojo
 
 #endif  // MOJO_APPS_JS_CONTENT_HANDLER_IMPL_H_