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

ash/system/user/tray_user.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 "ash/system/user/tray_user.h"
 
 #include <algorithm>
 #include <climits>
 #include <vector>
 
@@ skipping 52 matching lines @@
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/mouse_watcher.h"
 #include "ui/views/painter.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
 namespace {
 
 const int kUserDetailsVerticalPadding = 5;
 const int kUserCardVerticalPadding = 10;
-const int kInactiveUserCardVerticalPadding = 4;
 const int kProfileRoundedCornerRadius = 2;
 const int kUserIconSize = 27;
 const int kUserIconLargeSize = 32;
 const int kUserIconLargeCornerRadius = 2;
 const int kUserLabelToIconPadding = 5;
 // When using multi login, this spacing is added between user icons.
 const int kTrayLabelSpacing = 1;
 
 // When a hover border is used, it is starting this many pixels before the icon
 // position.
@@ skipping 1327 matching lines @@
       internal::GetRootWindowController(
           system_tray()->GetWidget()->GetNativeWindow()->GetRootWindow());
   if (controller && controller->shelf()) {
     UpdateAfterShelfAlignmentChange(
         controller->GetShelfLayoutManager()->GetAlignment());
   }
 }
 
 }  // namespace internal
 }  // namespace ash