support direct writing to top layer

include/core/SkBitmapDevice.h

 
 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBitmapDevice_DEFINED
 #define SkBitmapDevice_DEFINED
@@ skipping 200 matching lines @@
 
     /**
      * Implements readPixels API. The caller will ensure that:
      *  1. bitmap has pixel config kARGB_8888_Config.
      *  2. bitmap has pixels.
      *  3. The rectangle (x, y, x + bitmap->width(), y + bitmap->height()) is
      *     contained in the device bounds.
      */
     virtual bool onReadPixels(const SkBitmap&, int x, int y, SkCanvas::Config8888) SK_OVERRIDE;
     virtual bool onWritePixels(const SkImageInfo&, const void*, size_t, int, int) SK_OVERRIDE;
+    virtual void* onAccessPixels(SkImageInfo* info, size_t* rowBytes) SK_OVERRIDE;
 
     /** Called when this device is installed into a Canvas. Balanced by a call
         to unlockPixels() when the device is removed from a Canvas.
     */
     virtual void lockPixels() SK_OVERRIDE;
     virtual void unlockPixels() SK_OVERRIDE;
 
     /**
      *  Returns true if the device allows processing of this imagefilter. If
      *  false is returned, then the filter is ignored. This may happen for
@@ skipping 49 matching lines @@
 
     virtual SkSurface* newSurface(const SkImageInfo&) SK_OVERRIDE;
     virtual const void* peekPixels(SkImageInfo*, size_t* rowBytes) SK_OVERRIDE;
 
     SkBitmap    fBitmap;
 
     typedef SkBaseDevice INHERITED;
 };
 
 #endif // SkBitmapDevice_DEFINED