Allow CanvasSkia to bind to an existing SkCanvas.

ui/base/clipboard/clipboard_win.cc

 // 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.
 
 // Many of these functions are based on those found in
 // webkit/port/platform/PasteboardWin.cpp
 
 #include "ui/base/clipboard/clipboard.h"
 
 #include <shlobj.h>
@@ skipping 472 matching lines @@
       break;
     default:
       NOTREACHED();
   }
   const void* bitmap_bits = reinterpret_cast<const char*>(bitmap)
       + bitmap->bmiHeader.biSize + color_table_length * sizeof(RGBQUAD);
 
   gfx::CanvasSkia canvas(bitmap->bmiHeader.biWidth, bitmap->bmiHeader.biHeight,
                          false);
   {
-    skia::ScopedPlatformPaint scoped_platform_paint(&canvas);
+    skia::ScopedPlatformPaint scoped_platform_paint(canvas.sk_canvas());
     HDC dc = scoped_platform_paint.GetPlatformSurface();
     ::SetDIBitsToDevice(dc, 0, 0, bitmap->bmiHeader.biWidth,
                         bitmap->bmiHeader.biHeight, 0, 0, 0,
                         bitmap->bmiHeader.biHeight, bitmap_bits, bitmap,
                         DIB_RGB_COLORS);
   }
   // Windows doesn't really handle alpha channels well in many situations. When
   // the source image is < 32 bpp, we force the bitmap to be opaque. When the
   // source image is 32 bpp, the alpha channel might still contain garbage data.
   // Since Windows uses premultiplied alpha, we scan for instances where
   // (R, G, B) > A. If there are any invalid premultiplied colors in the image,
   // we assume the alpha channel contains garbage and force the bitmap to be
   // opaque as well. Note that this  heuristic will fail on a transparent bitmap
   // containing only black pixels...
-  const SkBitmap& device_bitmap = canvas.getDevice()->accessBitmap(true);
+  const SkBitmap& device_bitmap =
+      canvas.sk_canvas()->getDevice()->accessBitmap(true);
   {
     SkAutoLockPixels lock(device_bitmap);
     bool has_invalid_alpha_channel = bitmap->bmiHeader.biBitCount < 32 ||
         BitmapHasInvalidPremultipliedColors(device_bitmap);
     if (has_invalid_alpha_channel) {
       MakeBitmapOpaque(device_bitmap);
     }
   }
 
   return canvas.ExtractBitmap();
@@ skipping 196 matching lines @@
     clipboard_owner_ = ::CreateWindow(L"ClipboardOwnerWindowClass",
                                       L"ClipboardOwnerWindow",
                                       0, 0, 0, 0, 0,
                                       HWND_MESSAGE,
                                       0, 0, 0);
   }
   return clipboard_owner_;
 }
 
 }  // namespace ui