Add support for drawing window caption buttons on windows.

ui/native_theme/native_theme_win.h

 // 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.
 
 #ifndef UI_NATIVE_THEME_NATIVE_THEME_WIN_H_
 #define UI_NATIVE_THEME_NATIVE_THEME_WIN_H_
 
 // A wrapper class for working with custom XP/Vista themes provided in
 // uxtheme.dll.  This is a singleton class that can be grabbed using
 // NativeThemeWin::instance().
@@ skipping 241 matching lines @@
                         const TrackbarExtraParams& extra) const;
 
   HRESULT PaintProgressBar(HDC hdc,
                            const gfx::Rect& rect,
                            const ProgressBarExtraParams& extra) const;
 
   HRESULT PaintWindowResizeGripper(HDC hdc, const gfx::Rect& rect) const;
 
   HRESULT PaintTabPanelBackground(HDC hdc, const gfx::Rect& rect) const;
 
+  HRESULT PaintCaptionButton(HDC hdc,
+                             Part part,
+                             State state,
+                             const gfx::Rect&rect,
+                             const ExtraParams& extra) const;
+
   HRESULT PaintTextField(HDC hdc,
                          Part part,
                          State state,
                          const gfx::Rect& rect,
                          const TextFieldExtraParams& extra) const;
 
   // Paints a theme part, with support for scene scaling in high-DPI mode.
   // |theme| is the theme handle. |hdc| is the handle for the device context.
   // |part_id| is the identifier for the part (e.g. thumb gripper). |state_id|
   // is the identifier for the rendering state of the part (e.g. hover). |rect|
@@ skipping 97 matching lines @@
 
   // Is |is_using_high_contrast_| valid?
   mutable bool is_using_high_contrast_valid_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeThemeWin);
 };
 
 }  // namespace ui
 
 #endif  // UI_NATIVE_THEME_NATIVE_THEME_WIN_H_