Refactor the PlatformContext layer to have only one class.

skia/ext/platform_device_win.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef SKIA_EXT_PLATFORM_DEVICE_WIN_H_
 #define SKIA_EXT_PLATFORM_DEVICE_WIN_H_
 
 #include <windows.h>
 
 #include <vector>
 
 #include "SkDevice.h"
 
 class SkMatrix;
 class SkPath;
 class SkRegion;
 
 namespace skia {
 
 // A device is basically a wrapper around SkBitmap that provides a surface for
 // SkCanvas to draw into. Our device provides a surface Windows can also write
 // to. It also provides functionality to play well with GDI drawing functions.
 // This class is abstract and must be subclassed. It provides the basic
 // interface to implement it either with or without a bitmap backend.
-class PlatformDeviceWin : public SkDevice {
+class PlatformDevice : public SkDevice {
  public:
+  typedef HDC PlatformSurface;
+
   // The DC that corresponds to the bitmap, used for GDI operations drawing
   // into the bitmap. This is possibly heavyweight, so it should be existant
   // only during one pass of rendering.
   virtual HDC getBitmapDC() = 0;
 
   // Draws to the given screen DC, if the bitmap DC doesn't exist, this will
   // temporarily create it. However, if you have created the bitmap DC, it will
   // be more efficient if you don't free it until after this call so it doesn't
   // have to be created twice.  If src_rect is null, then the entirety of the
   // source device will be copied.
@@ skipping 18 matching lines @@
 
  protected:
   // Arrays must be inside structures.
   struct CubicPoints {
     SkPoint p[4];
   };
   typedef std::vector<CubicPoints> CubicPath;
   typedef std::vector<CubicPath> CubicPaths;
 
   // Forwards |bitmap| to SkDevice's constructor.
-  PlatformDeviceWin(const SkBitmap& bitmap);
+  PlatformDevice(const SkBitmap& bitmap);
 
   // Loads the specified Skia transform into the device context, excluding
   // perspective (which GDI doesn't support).
   static void LoadTransformToDC(HDC dc, const SkMatrix& matrix);
 
   // Transforms SkPath's paths into a series of cubic path.
   static bool SkPathToCubicPaths(CubicPaths* paths, const SkPath& skpath);
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_DEVICE_WIN_H_