Introduce SystemMenuButton for Ash material design

ash/common/system/tray/special_popup_row.h

 // Copyright (c) 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.
 
 #ifndef ASH_COMMON_SYSTEM_TRAY_SPECIAL_POPUP_ROW_H_
 #define ASH_COMMON_SYSTEM_TRAY_SPECIAL_POPUP_ROW_H_
 
 #include "ash/ash_export.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "base/macros.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/views/view.h"
 
 namespace views {
 class Button;
 class ButtonListener;
-class ImageButton;
 class Label;
 class ToggleButton;
 }
 
 namespace ash {
+class SystemMenuButton;
 class ThrobberView;
 class TrayItemView;
 class TrayPopupHeaderButton;
 class ViewClickListener;
 
 // For material design, this class represents the top title row for detailed
 // views and handles the creation and layout of its elements (back button,
 // title, settings button, and possibly other buttons). For non-MD, this class
 // represents the bottom row of detailed views and the bottom row of the
 // system menu (date, help, power, and lock). This row has a fixed height.
@@ skipping 41 matching lines @@
 
   // Used to add views to |views_before_content_container_| and
   // |views_after_content_container_|, respectively. Views are added to both
   // containers in a left-to-right order.
   void AddViewBeforeContent(views::View* view);
   void AddViewAfterContent(views::View* view);
   void AddViewAfterContent(views::View* view, bool add_separator);
 
   void SetTextLabelMd(int string_id, ViewClickListener* listener);
   void SetTextLabelNonMd(int string_id, ViewClickListener* listener);
-  views::ImageButton* AddImageButton(views::ButtonListener* listener,
-                                     const gfx::VectorIcon& icon,
-                                     int accessible_name_id,
-                                     bool after_content);
+  SystemMenuButton* AddSystemMenuButton(views::ButtonListener* listener,
+                                        const gfx::VectorIcon& icon,
+                                        int accessible_name_id,
+                                        bool after_content);
 
   // The container for the views positioned before |content_|.
   views::View* views_before_content_container_;
 
   // The main content of this row, typically a label.
   views::View* content_;
 
   // The container for the views positioned after |content_|.
   views::View* views_after_content_container_;
 
   // A pointer to the label which is parented to |content_|; this is non-null
   // only if this row's content is a single label. Not owned.
   views::Label* label_;
 
   DISALLOW_COPY_AND_ASSIGN(SpecialPopupRow);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SPECIAL_POPUP_ROW_H_