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

ui/display/chromeos/x11/native_display_delegate_x11.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 "ui/display/chromeos/x11/native_display_delegate_x11.h"
 
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
 #include <X11/extensions/dpms.h>
 #include <X11/extensions/Xrandr.h>
@@ skipping 61 matching lines @@
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeDisplayDelegateX11::HelperDelegateX11
 
 class NativeDisplayDelegateX11::HelperDelegateX11
     : public NativeDisplayDelegateX11::HelperDelegate {
  public:
   HelperDelegateX11(NativeDisplayDelegateX11* delegate) : delegate_(delegate) {}
-  virtual ~HelperDelegateX11() {}
+  ~HelperDelegateX11() override {}
 
   // NativeDisplayDelegateX11::HelperDelegate overrides:
-  virtual void UpdateXRandRConfiguration(const base::NativeEvent& event)
-      override {
+  void UpdateXRandRConfiguration(const base::NativeEvent& event) override {
     XRRUpdateConfiguration(event);
   }
-  virtual const std::vector<DisplaySnapshot*>& GetCachedDisplays() const
-      override {
+  const std::vector<DisplaySnapshot*>& GetCachedDisplays() const override {
     return delegate_->cached_outputs_.get();
   }
-  virtual void NotifyDisplayObservers() override {
+  void NotifyDisplayObservers() override {
     FOR_EACH_OBSERVER(
         NativeDisplayObserver, delegate_->observers_, OnConfigurationChanged());
   }
 
  private:
   NativeDisplayDelegateX11* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(HelperDelegateX11);
 };
 
@@ skipping 538 matching lines @@
   XSetForeground(display_, gc, color.pixel);
   XSetFillStyle(display_, gc, FillSolid);
   int width = DisplayWidth(display_, DefaultScreen(display_));
   int height = DisplayHeight(display_, DefaultScreen(display_));
   XFillRectangle(display_, window_, gc, 0, 0, width, height);
   XFreeGC(display_, gc);
   XFreeColors(display_, colormap, &color.pixel, 1, 0);
 }
 
 }  // namespace ui