Consolidate Windows bitmap and DC code

ui/native_theme/native_theme_win.h

Index: ui/native_theme/native_theme_win.h
diff --git a/ui/native_theme/native_theme_win.h b/ui/native_theme/native_theme_win.h
index 03483650bc57ab4f54b36911a12a9fb7621e5696..a1fe5bbebfd92c495954ab7249f72983085fbae7 100644
--- a/ui/native_theme/native_theme_win.h
+++ b/ui/native_theme/native_theme_win.h
@@ -130,8 +130,8 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
   void PaintMenuGutter(SkCanvas* canvas, const gfx::Rect& rect) const;
   void PaintMenuBackground(SkCanvas* canvas, const gfx::Rect& rect) const;
 
-  // Paint directly to canvas' HDC.
-  void PaintDirect(SkCanvas* canvas,
+  // Paint directly to HDC.
+  void PaintDirect(HDC hdc,
                    Part part,
                    State state,
                    const gfx::Rect& rect,
@@ -140,7 +140,7 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
   // Create a temporary HDC, paint to that, clean up the alpha values in the
   // temporary HDC, and then blit the result to canvas.  This is to work around
   // the fact that Windows XP and some classic themes give bogus alpha values.
-  void PaintIndirect(SkCanvas* canvas,
+  void PaintIndirect(HDC hdc,
                      Part part,
                      State state,
                      const gfx::Rect& rect,
@@ -231,8 +231,7 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
   // Paints a scrollbar track section.  |align_rect| is only used in classic
   // mode, and makes sure the checkerboard pattern in |target_rect| is aligned
   // with one presumed to be in |align_rect|.
-  HRESULT PaintScrollbarTrack(SkCanvas* canvas,
-                              HDC hdc,
+  HRESULT PaintScrollbarTrack(HDC hdc,
                               Part part,
                               State state,
                               const gfx::Rect& rect,
@@ -244,8 +243,7 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
                           const gfx::Rect& rect,
                           const InnerSpinButtonExtraParams& extra) const;
 
-  HRESULT PaintTrackbar(SkCanvas* canvas,
-                        HDC hdc,
+  HRESULT PaintTrackbar(HDC hdc,
                         Part part,
                         State state,
                         const gfx::Rect& rect,