keep only one typedef for the native drawing context

skia/ext/bitmap_platform_device_win.h

Index: skia/ext/bitmap_platform_device_win.h
diff --git a/skia/ext/bitmap_platform_device_win.h b/skia/ext/bitmap_platform_device_win.h
index dd1aedb9a56aced209f5bd46f37e9dc001f341ee..b750e166ce5ab3d0cdd60888fd1c950233ba4564 100644
--- a/skia/ext/bitmap_platform_device_win.h
+++ b/skia/ext/bitmap_platform_device_win.h
@@ -47,8 +47,8 @@ class SK_API BitmapPlatformDevice : public SkBitmapDevice,
   // PlatformDevice override
   // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
   // bitmap DC may be lazily created.
-  PlatformSurface BeginPlatformPaint(const SkMatrix& transform,
-                                     const SkIRect& clip_bounds) override;
+  NativeDrawingContext BeginPlatformPaint(const SkMatrix& transform,
+                                          const SkIRect& clip_bounds) override;
 
   // Private constructor.
   BitmapPlatformDevice(HBITMAP hbitmap, const SkBitmap& bitmap);