use new readPixels, as old version using Config8888 is deprecated

Source/platform/graphics/GraphicsContext.h

 /*
  * Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008-2009 Torch Mobile, Inc.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 186 matching lines @@
     void setUpdatingControlTints(bool updatingTints) { m_updatingControlTints = updatingTints; }
 
     AnnotationModeFlags annotationMode() const { return m_annotationMode; }
     void setAnnotationMode(const AnnotationModeFlags mode) { m_annotationMode = mode; }
 
     SkColorFilter* colorFilter();
     void setColorFilter(ColorFilter);
     // ---------- End state management methods -----------------
 
     // Get the contents of the image buffer
-    bool readPixels(SkBitmap*, int, int, SkCanvas::Config8888 = SkCanvas::kNative_Premul_Config8888);
+    bool readPixels(const SkImageInfo&, void* pixels, size_t rowBytes, int x, int y);
 
     // Sets up the paint for the current fill style.
     void setupPaintForFilling(SkPaint*) const;
 
     // Sets up the paint for the current stroke style.
     void setupPaintForStroking(SkPaint*) const;
 
     // These draw methods will do both stroking and filling.
     // FIXME: ...except drawRect(), which fills properly but always strokes
     // using a 1-pixel stroke inset from the rect borders (of the correct
@@ skipping 283 matching lines @@
     // FIXME: Make this go away: crbug.com/236892
     bool m_updatingControlTints : 1;
     bool m_accelerated : 1;
     bool m_isCertainlyOpaque : 1;
     bool m_printing : 1;
 };
 
 } // namespace WebCore
 
 #endif // GraphicsContext_h