Standardize usage of virtual/override/final in mojo/

mojo/apps/js/content_handler_impl.cc

 // 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.
 
 #include "mojo/apps/js/content_handler_impl.h"
 
 #include "mojo/apps/js/application_delegate_impl.h"
 #include "mojo/apps/js/js_app.h"
 #include "mojo/common/data_pipe_utils.h"
 
 namespace mojo {
 namespace apps {
 
 class ContentHandlerJSApp : public JSApp {
  public:
   ContentHandlerJSApp(ApplicationDelegateImpl* app_delegate_impl,
                       URLResponsePtr content)
       : JSApp(app_delegate_impl),
         content_(content.Pass()) {
   }
 
-  virtual bool Load(std::string* source, std::string* file_name) override {
+  bool Load(std::string* source, std::string* file_name) override {
     *file_name = content_->url;
     if (content_.is_null())
       return false;
     return common::BlockingCopyToString(content_->body.Pass(), source);
   }
 
  private:
   URLResponsePtr content_;
 };
 
 
 ContentHandlerImpl::ContentHandlerImpl(ApplicationDelegateImpl* app)
     : app_delegate_impl_(app) {
 }
 
 ContentHandlerImpl::~ContentHandlerImpl() {
 }
 
 void ContentHandlerImpl::OnConnect(
     const mojo::String& requestor_url,
     URLResponsePtr content,
     InterfaceRequest<ServiceProvider> service_provider) {
   scoped_ptr<JSApp> js_app(
       new ContentHandlerJSApp(app_delegate_impl_, content.Pass()));
   app_delegate_impl_->StartJSApp(js_app.Pass());
 }
 
 }  // namespace apps
 }  // namespace mojo