linux and chromeos: Turn on -Wunused-const-variable.

ui/views/controls/menu/menu_scroll_view_container.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/views/controls/menu/menu_scroll_view_container.h"
 
 #include "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/gfx/canvas.h"
 #include "ui/views/border.h"
 #include "ui/views/bubble/bubble_border.h"
 #include "ui/views/controls/menu/menu_config.h"
 #include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 #include "ui/views/controls/menu/submenu_view.h"
 #include "ui/views/round_rect_painter.h"
 
 #if defined(USE_AURA)
 #include "ui/native_theme/native_theme_aura.h"
 #endif
 
 using ui::NativeTheme;
 
-// Height of the scroll arrow.
-// This goes up to 4 with large fonts, but this is close enough for now.
-static const int scroll_arrow_height = 3;
-
 namespace views {
 
 namespace {
 
 static const int kBorderPaddingDueToRoundedCorners = 1;
 
 // MenuScrollButton ------------------------------------------------------------
 
 // MenuScrollButton is used for the scroll buttons when not all menu items fit
 // on screen. MenuScrollButton forwards appropriate events to the
@@ skipping 293 matching lines @@
     case views::MenuItemView::BUBBLE_ABOVE:
       return BubbleBorder::BOTTOM_CENTER;
     case views::MenuItemView::BUBBLE_BELOW:
       return BubbleBorder::TOP_CENTER;
     default:
       return BubbleBorder::NONE;
   }
 }
 
 }  // namespace views