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

ash/display/display_configurator_animation.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 "ash/display/display_configurator_animation.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "base/bind.h"
 #include "base/stl_util.h"
@@ skipping 45 matching lines @@
   // The actual observer to listen each animation completion.
   class Observer : public ui::LayerAnimationObserver {
    public:
     Observer(ui::LayerAnimator* animator,
              CallbackRunningObserver* observer)
         : animator_(animator),
           observer_(observer) {}
 
    protected:
     // ui::LayerAnimationObserver overrides:
-    virtual void OnLayerAnimationEnded(
-        ui::LayerAnimationSequence* sequence) override {
+    void OnLayerAnimationEnded(ui::LayerAnimationSequence* sequence) override {
       animator_->RemoveObserver(this);
       observer_->OnSingleTaskCompleted();
     }
-    virtual void OnLayerAnimationAborted(
+    void OnLayerAnimationAborted(
         ui::LayerAnimationSequence* sequence) override {
       animator_->RemoveObserver(this);
       observer_->OnSingleTaskAborted();
     }
-    virtual void OnLayerAnimationScheduled(
-        ui::LayerAnimationSequence* sequence) override {
-    }
-    virtual bool RequiresNotificationWhenAnimatorDestroyed() const override {
+    void OnLayerAnimationScheduled(
+        ui::LayerAnimationSequence* sequence) override {}
+    bool RequiresNotificationWhenAnimatorDestroyed() const override {
       return true;
     }
 
    private:
     ui::LayerAnimator* animator_;
     CallbackRunningObserver* observer_;
 
     DISALLOW_COPY_AND_ASSIGN(Observer);
   };
 
@@ skipping 129 matching lines @@
   if (timer_) {
     timer_->Stop();
     timer_.reset();
   }
   STLDeleteContainerPairSecondPointers(
       hiding_layers_.begin(), hiding_layers_.end());
   hiding_layers_.clear();
 }
 
 }  // namespace ash