Plumbs through support for painting the scrollbarcorner

ui/native_theme/native_theme_base.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_BASE_H_
 #define UI_NATIVE_THEME_NATIVE_THEME_BASE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 43 matching lines @@
       State state,
       const ScrollbarTrackExtraParams& extra_params,
       const gfx::Rect& rect) const;
   // Draw the scrollbar thumb over the track.
   virtual void PaintScrollbarThumb(
       SkCanvas* canvas,
       Part part,
       State state,
       const gfx::Rect& rect) const;
 
+  virtual void PaintScrollbarCorner(SkCanvas* canvas,
+                                    State state,
+                                    const gfx::Rect& rect) const;
+
   virtual void PaintCheckbox(
       SkCanvas* canvas,
       State state,
       const gfx::Rect& rect,
       const ButtonExtraParams& button) const;
 
   virtual void PaintRadio(
       SkCanvas* canvas,
       State state,
       const gfx::Rect& rect,
@@ skipping 111 matching lines @@
 
   unsigned int scrollbar_width_;
   unsigned int scrollbar_button_length_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeThemeBase);
 };
 
 }  // namespace ui
 
 #endif  // UI_NATIVE_THEME_NATIVE_THEME_BASE_H_