Move logic from NativeImageSkia to GraphicsContext and SkiaUtils

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 219 matching lines @@
     // It is never clerared by the context.
     void setTrackTextRegion(bool track) { m_trackTextRegion = track; }
     const SkRect& textRegion() const { return m_textRegion; }
 
     bool updatingControlTints() const { return m_updatingControlTints; }
     void setUpdatingControlTints(bool updatingTints) { m_updatingControlTints = updatingTints; }
 
     AnnotationModeFlags annotationMode() const { return m_annotationMode; }
     void setAnnotationMode(const AnnotationModeFlags mode) { m_annotationMode = mode; }
 
-    SkColorFilter* colorFilter();
+    SkColorFilter* colorFilter() const;
     void setColorFilter(ColorFilter);
     // ---------- End state management methods -----------------
 
     // Get the contents of the image buffer
     bool readPixels(const SkImageInfo&, void* pixels, size_t rowBytes, int x, int y);
 
     // Get the current fill style.
     const SkPaint& fillPaint() const { return immutableState()->fillPaint(); }
 
     // Get the current stroke style.
@@ skipping 153 matching lines @@
 
     // Create an image buffer compatible with this context, with suitable resolution
     // for drawing into the buffer and then into this context.
     PassOwnPtr<ImageBuffer> createRasterBuffer(const IntSize&, OpacityMode = NonOpaque) const;
 
     static void adjustLineToPixelBoundaries(FloatPoint& p1, FloatPoint& p2, float strokeWidth, StrokeStyle);
 
     void beginAnnotation(const AnnotationList&);
     void endAnnotation();
 
+    void preparePaint(

[jbroman, 2014/07/23 15:48:59]

drive-by: please use a more descriptive name than "preparePaint". What kind of
paint is this preparing, and where should it be used? It's not obvious what
srcRect and destRect mean in this context.

[Rémi Piotaix, 2014/07/23 17:28:22]

Done.

+        SkPaint*,
+        const SkRect& srcRect,
+        const SkRect& destRect,
+        CompositeOperator,
+        blink::WebBlendMode,
+        bool isLazyDecoded = false) const;
 private:
     const GraphicsContextState* immutableState() const { return m_paintState; }
 
     GraphicsContextState* mutableState()
     {
         realizePaintSave();
         return m_paintState;
     }
 
     static void setPathFromConvexPoints(SkPath*, size_t, const FloatPoint*);
@@ skipping 105 matching lines @@
     bool m_updatingControlTints : 1;
     bool m_accelerated : 1;
     bool m_isCertainlyOpaque : 1;
     bool m_printing : 1;
     bool m_antialiasHairlineImages : 1;
 };
 
 } // namespace blink
 
 #endif // GraphicsContext_h