Consolidate some more ash tray constants.

ash/common/system/tray/tray_popup_header_button.cc

 // Copyright 2013 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/common/system/tray/tray_popup_header_button.h"
 
 #include "ash/common/ash_constants.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/views/background.h"
@@ skipping 39 matching lines @@
       bundle.GetImageNamed(disabled_resource_id_hover).ToImageSkia());
 }
 
 TrayPopupHeaderButton::~TrayPopupHeaderButton() {}
 
 const char* TrayPopupHeaderButton::GetClassName() const {
   return kViewClassName;
 }
 
 gfx::Size TrayPopupHeaderButton::GetPreferredSize() const {
-  int size = GetTrayConstant(TRAY_POPUP_ITEM_MIN_HEIGHT);
-  return gfx::Size(size, size);
+  return gfx::Size(kTrayPopupItemMinHeight, kTrayPopupItemMinHeight);
 }
 
 void TrayPopupHeaderButton::StateChanged(ButtonState old_state) {
   if (state() == STATE_HOVERED || state() == STATE_PRESSED) {
     set_background(views::Background::CreateSolidBackground(
         kTrayPopupHoverBackgroundColor));
   } else {
     set_background(nullptr);
   }
   SchedulePaint();
 }
 
 void TrayPopupHeaderButton::Initialize(const gfx::ImageSkia& icon,
                                        int accessible_name_id) {
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   SetImage(views::Button::STATE_NORMAL, icon);
   SetImageAlignment(views::ImageButton::ALIGN_CENTER,
                     views::ImageButton::ALIGN_MIDDLE);
   SetAccessibleName(bundle.GetLocalizedString(accessible_name_id));
   SetFocusForPlatform();
 
   SetFocusPainter(views::Painter::CreateSolidFocusPainter(
       kFocusBorderColor, gfx::Insets(1, 2, 2, 3)));
 }
 
 }  // namespace ash