Standardize usage of virtual/override/final specifiers.

ui/app_list/views/page_switcher.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 "ui/app_list/views/page_switcher.h"
 
 #include <algorithm>
 
 #include "third_party/skia/include/core/SkPath.h"
 #include "ui/app_list/app_list_constants.h"
@@ skipping 18 matching lines @@
 const int kButtonCornerRadius = 2;
 const int kButtonStripPadding = 20;
 
 class PageSwitcherButton : public views::CustomButton {
  public:
   explicit PageSwitcherButton(views::ButtonListener* listener)
       : views::CustomButton(listener),
         button_width_(kMaxButtonWidth),
         selected_range_(0) {
   }
-  virtual ~PageSwitcherButton() {}
+  ~PageSwitcherButton() override {}
 
   void SetSelectedRange(double selected_range) {
     if (selected_range_ == selected_range)
       return;
 
     selected_range_ = selected_range;
     SchedulePaint();
   }
 
   void set_button_width(int button_width) { button_width_ = button_width; }
 
   // Overridden from views::View:
-  virtual gfx::Size GetPreferredSize() const override {
+  gfx::Size GetPreferredSize() const override {
     return gfx::Size(button_width_, kButtonHeight);
   }
 
-  virtual void OnPaint(gfx::Canvas* canvas) override {
+  void OnPaint(gfx::Canvas* canvas) override {
     if (state() == STATE_HOVERED)
       PaintButton(canvas, kPagerHoverColor);
     else
       PaintButton(canvas, kPagerNormalColor);
   }
 
  private:
   // Paints a button that has two rounded corner at bottom.
   void PaintButton(gfx::Canvas* canvas, SkColor base_color) {
     gfx::Rect rect(GetContentsBounds());
@@ skipping 191 matching lines @@
     remaining = -remaining;
     progress = -progress;
   }
 
   GetButtonByIndex(buttons_, current_page)->SetSelectedRange(remaining);
   if (model_->is_valid_page(target_page))
     GetButtonByIndex(buttons_, target_page)->SetSelectedRange(progress);
 }
 
 }  // namespace app_list