Update {virtual,override} to follow C++11 style in ppapi.

ppapi/proxy/plugin_globals.cc

 // Copyright (c) 2012 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 "ppapi/proxy/plugin_globals.h"
 
 #include "base/task_runner.h"
 #include "base/threading/thread.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_sender.h"
@@ skipping 13 matching lines @@
 
 // It performs necessary locking/unlocking of the proxy lock, and forwards all
 // messages to the underlying sender.
 class PluginGlobals::BrowserSender : public IPC::Sender {
  public:
   // |underlying_sender| must outlive this object.
   explicit BrowserSender(IPC::Sender* underlying_sender)
       : underlying_sender_(underlying_sender) {
   }
 
-  virtual ~BrowserSender() {}
+  ~BrowserSender() override {}
 
   // IPC::Sender implementation.
-  virtual bool Send(IPC::Message* msg) override {
+  bool Send(IPC::Message* msg) override {
     if (msg->is_sync()) {
       // Synchronous messages might be re-entrant, so we need to drop the lock.
       ProxyAutoUnlock unlock;
       return underlying_sender_->Send(msg);
     }
 
     return underlying_sender_->Send(msg);
   }
 
  private:
@@ skipping 209 matching lines @@
   return true;
 }
 
 void PluginGlobals::OnReleaseKeepaliveThrottle() {
   ppapi::ProxyLock::AssertAcquiredDebugOnly();
   plugin_recently_active_ = false;
 }
 
 }  // namespace proxy
 }  // namespace ppapi