Standardize usage of virtual/override/final in mojo/

mojo/public/cpp/application/lib/application_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/public/cpp/application/application_impl.h"
 
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/lib/service_registry.h"
 #include "mojo/public/cpp/bindings/interface_ptr.h"
 #include "mojo/public/cpp/environment/logging.h"
 
 namespace mojo {
 
 class ApplicationImpl::ShellPtrWatcher : public ErrorHandler {
  public:
   ShellPtrWatcher(ApplicationImpl* impl) : impl_(impl) {}
 
-  virtual ~ShellPtrWatcher() {}
+  ~ShellPtrWatcher() override {}
 
-  virtual void OnConnectionError() override { impl_->OnShellError(); }
+  void OnConnectionError() override { impl_->OnShellError(); }
 
  private:
   ApplicationImpl* impl_;
   MOJO_DISALLOW_COPY_AND_ASSIGN(ShellPtrWatcher);
 };
 
 ApplicationImpl::ApplicationImpl(ApplicationDelegate* delegate,
                                  ScopedMessagePipeHandle shell_handle)
     : initialized_(false), delegate_(delegate), shell_watch_(nullptr) {
   BindShell(shell_handle.Pass());
@@ skipping 69 matching lines @@
   internal::ServiceRegistry* registry = new internal::ServiceRegistry(
       this, requestor_url, service_provider.Pass());
   if (!delegate_->ConfigureIncomingConnection(registry)) {
     delete registry;
     return;
   }
   incoming_service_registries_.push_back(registry);
 }
 
 }  // namespace mojo