Fix "unused variable" warnings.

ui/app_list/views/tile_item_view.h

 // 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.
 
 #ifndef UI_APP_LIST_VIEWS_TILE_ITEM_VIEW_H_
 #define UI_APP_LIST_VIEWS_TILE_ITEM_VIEW_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "third_party/skia/include/core/SkColor.h"
@@ skipping 53 matching lines @@
 
  private:
   void UpdateBackgroundColor();
 
   // Overridden from views::View:
   gfx::Size GetPreferredSize() const override;
   bool GetTooltipText(const gfx::Point& p,
                       base::string16* tooltip) const override;
 
   SkColor parent_background_color_;
-  HoverStyle hover_style_;
   std::unique_ptr<ImageShadowAnimator> image_shadow_animator_;
 
   views::ImageView* icon_;  // Owned by views hierarchy.
   views::Label* title_;     // Owned by views hierarchy.
 
   bool selected_;
 
   DISALLOW_COPY_AND_ASSIGN(TileItemView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_TILE_ITEM_VIEW_H_