Move chromeos code to namespace chromeos.

chrome/browser/chromeos/status_area_button.h

 // Copyright (c) 2006-2008 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 CHROME_BROWSER_CHROMEOS_STATUS_AREA_BUTTON_H_
 #define CHROME_BROWSER_CHROMEOS_STATUS_AREA_BUTTON_H_
 
 #include "views/controls/button/menu_button.h"
 #include "views/controls/menu/view_menu_delegate.h"
 
+namespace chromeos {
+
 // Button to be used to represent status and allow menus to be popped up.
 // Shows current button state by drawing a border around the current icon.
 class StatusAreaButton : public views::MenuButton {
  public:
   explicit StatusAreaButton(views::ViewMenuDelegate* menu_delegate);
   virtual ~StatusAreaButton() {}
   virtual void Paint(gfx::Canvas* canvas, bool for_drag);
 
  protected:
   // Draws the icon for this status area button on the canvas.
   // Subclasses should override this method if they need to draw their own icon.
   // Otherwise, just call SetIcon() and the it will be handled for you.
   virtual void DrawIcon(gfx::Canvas* canvas);
 
   DISALLOW_COPY_AND_ASSIGN(StatusAreaButton);
 };
 
+}  // namespace chromeos
+
 #endif  // CHROME_BROWSER_CHROMEOS_STATUS_AREA_BUTTON_H_