Refactor window frame painting into a window background class

ui/views/window/custom_frame_view.h

 // Copyright (c) 2011 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_VIEWS_WINDOW_CUSTOM_FRAME_VIEW_H_
 #define UI_VIEWS_WINDOW_CUSTOM_FRAME_VIEW_H_
 #pragma once
 
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/non_client_view.h"
 
+class SkBitmap;
 namespace gfx {
 class Canvas;
 class Font;
 class Size;
 class Path;
 class Point;
 }
 
 namespace views {
 
+class FrameBackground;
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // CustomFrameView
 //
 //  A ChromeView that provides the non client frame for Windows. This means
 //  rendering the non-standard window caption, border, and controls.
 //
 ////////////////////////////////////////////////////////////////////////////////
 class CustomFrameView : public NonClientFrameView,
                         public ButtonListener {
@@ skipping 51 matching lines @@
   // Returns true if the client edge should be drawn. This is true if
   // the window delegate wants a client edge and we are not maxmized.
   bool ShouldShowClientEdge() const;
 
   // Paint various sub-components of this view.
   void PaintRestoredFrameBorder(gfx::Canvas* canvas);
   void PaintMaximizedFrameBorder(gfx::Canvas* canvas);
   void PaintTitleBar(gfx::Canvas* canvas);
   void PaintRestoredClientEdge(gfx::Canvas* canvas);
 
+  // Compute aspects of the frame needed to paint the frame background.
+  SkColor GetFrameColor() const;
+  SkBitmap* GetFrameBitmap() const;
+
   // Layout various sub-components of this view.
   void LayoutWindowControls();
   void LayoutTitleBar();
   void LayoutClientView();
 
   // The bounds of the client view, in this view's coordinates.
   gfx::Rect client_view_bounds_;
 
   // The layout rect of the title, if visible.
   gfx::Rect title_bounds_;
 
   // Window controls.
   ImageButton* close_button_;
   ImageButton* restore_button_;
   ImageButton* maximize_button_;
   ImageButton* minimize_button_;
   ImageButton* window_icon_;
   bool should_show_minmax_buttons_;
   bool should_show_client_edge_;
 
   // The window that owns this view.
   Widget* frame_;
 
+  // Background painter for the window frame.
+  scoped_ptr<FrameBackground> frame_background_;
+
   // Initialize various static resources.
   static void InitClass();
   static gfx::Font* title_font_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomFrameView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WINDOW_CUSTOM_FRAME_VIEW_H_