ui/gfx: Make gfx::Canvas inherit from gfx::CanvasSkia.

ui/views/controls/menu/menu_item_view_win.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
 #include "ui/views/controls/menu/menu_item_view.h"
 
 #include <uxtheme.h>
 #include <Vssym32.h>
 
 #include "grit/ui_strings.h"
 #include "ui/gfx/canvas_skia.h"
@@ skipping 73 matching lines @@
   const gfx::Font& font = GetFont();
   int accel_width = parent_menu_item_->GetSubmenu()->max_accelerator_width();
   int width = this->width() - item_right_margin_ - label_start_ - accel_width;
   gfx::Rect text_bounds(label_start_, top_margin, width, font.GetHeight());
   text_bounds.set_x(GetMirroredXForRect(text_bounds));
   if (mode == PB_FOR_DRAG) {
     // With different themes, it's difficult to tell what the correct
     // foreground and background colors are for the text to draw the correct
     // halo. Instead, just draw black on white, which will look good in most
     // cases.
-    canvas->AsCanvasSkia()->DrawStringWithHalo(
+    canvas->DrawStringWithHalo(
         title(), font, 0x00000000, 0xFFFFFFFF, text_bounds.x(),
         text_bounds.y(), text_bounds.width(), text_bounds.height(),
         GetRootMenuItem()->GetDrawStringFlags());
   } else {
     canvas->DrawStringInt(title(), font, fg_color,
                           text_bounds.x(), text_bounds.y(), text_bounds.width(),
                           text_bounds.height(),
                           GetRootMenuItem()->GetDrawStringFlags());
   }
 
@@ skipping 56 matching lines @@
       NativeTheme::kMenuCheckBackground, state, bg_bounds, extra);
 
   // And the check.
   gfx::Rect icon_bounds(icon_x / 2, icon_y, icon_width, icon_height);
   AdjustBoundsForRTLUI(&icon_bounds);
   NativeTheme::instance()->Paint(canvas->GetSkCanvas(),
       NativeTheme::kMenuCheck, state, bg_bounds, extra);
 }
 
 }  // namespace views