Prefer to forward-declare GraphicsContext in headers.

Source/core/rendering/shapes/Shape.cpp

 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. 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 21 matching lines @@
 
 #include "core/css/BasicShapeFunctions.h"
 #include "core/fetch/ImageResource.h"
 #include "core/rendering/shapes/BoxShape.h"
 #include "core/rendering/shapes/PolygonShape.h"
 #include "core/rendering/shapes/RasterShape.h"
 #include "core/rendering/shapes/RectangleShape.h"
 #include "core/rendering/style/RenderStyle.h"
 #include "platform/LengthFunctions.h"
 #include "platform/geometry/FloatSize.h"
+#include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/WindRule.h"
 #include "wtf/MathExtras.h"
 #include "wtf/OwnPtr.h"
 
 namespace WebCore {
 
 static PassOwnPtr<Shape> createInsetShape(const FloatRoundedRect& bounds)
 {
     ASSERT(bounds.rect().width() >= 0 && bounds.rect().height() >= 0);
@@ skipping 169 matching lines @@
     FloatRect rect(0, 0, roundedRect.rect().width(), roundedRect.rect().height());
     FloatRoundedRect bounds(rect, roundedRect.radii());
     OwnPtr<Shape> shape = createInsetShape(bounds);
     shape->m_writingMode = writingMode;
     shape->m_margin = margin;
 
     return shape.release();
 }
 
 } // namespace WebCore