keep only one typedef for the native drawing context

ui/gfx/blit.cc

 // 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/gfx/blit.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "build/build_config.h"
@@ skipping 58 matching lines @@
 
 void ScrollCanvas(SkCanvas* canvas,
                   const gfx::Rect& in_clip,
                   const gfx::Vector2d& offset) {
   DCHECK(!HasClipOrTransform(*canvas));  // Don't support special stuff.
 #if defined(OS_WIN)
   // If we have a PlatformCanvas, we should use ScrollDC. Otherwise, fall
   // through to the software implementation.
   if (skia::SupportsPlatformPaint(canvas)) {
     skia::ScopedPlatformPaint scoped_platform_paint(canvas);
-    HDC hdc = scoped_platform_paint.GetPlatformSurface();
+    HDC hdc = scoped_platform_paint.GetNativeDrawingContext();
 
     RECT damaged_rect;
     RECT r = in_clip.ToRECT();
     ScrollDC(hdc, offset.x(), offset.y(), NULL, &r, NULL, &damaged_rect);
     return;
   }
 #endif  // defined(OS_WIN)
   // For non-windows, always do scrolling in software.
   // Cairo has no nice scroll function so we do our own. On Mac it's possible to
   // use platform scroll code, but it's complex so we just use the same path
@@ skipping 34 matching lines @@
     // Fortunately, memmove already handles this for us.
     for (int y = 0; y < dest_rect.height(); y++) {
       memmove(pixmap.writable_addr32(dest_rect.x(), dest_rect.y() + y),
               pixmap.addr32(src_rect.x(), src_rect.y() + y),
               row_bytes);
     }
   }
 }
 
 }  // namespace gfx