Make it possible to custom-paint without an Element.

sky/engine/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 976 matching lines @@
         contextScaling.setHeight(1);
 
     if (borderObscuresBackgroundEdge(contextScaling))
         return BackgroundBleedShrinkBackground;
     if (borderObscuresBackground() && backgroundHasOpaqueTopLayer())
         return BackgroundBleedBackgroundOverBorder;
 
     return BackgroundBleedClipBackground;
 }
 
+void RenderBox::paintCustomPainting(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
+{
+    LayoutRect paintRect = borderBoxRect();
+    paintRect.moveBy(paintOffset);
+    // TODO(abarth): Currently we only draw m_customPainting if we happen to
+    // have a box decoration or a background.
+    if (m_customPainting)
+        paintInfo.context->drawDisplayList(m_customPainting.get(), paintRect.location());
+}
+
 void RenderBox::paintBoxDecorationBackground(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     LayoutRect paintRect = borderBoxRect();
     paintRect.moveBy(paintOffset);
     paintBoxDecorationBackgroundWithRect(paintInfo, paintOffset, paintRect);
-    // TODO(abarth): Currently we only draw m_customPainting if we happen to
-    // have a box decoration or a background. Instead, we should probably have
-    // another function like paintBoxDecorationBackground that subclasses can
-    // call to draw m_customPainting.
-    if (m_customPainting)
-        paintInfo.context->drawDisplayList(m_customPainting.get(), paintRect.location());
+    paintCustomPainting(paintInfo, paintOffset);
 }
 
 void RenderBox::paintBoxDecorationBackgroundWithRect(PaintInfo& paintInfo, const LayoutPoint& paintOffset, const LayoutRect& paintRect)
 {
     RenderStyle* style = this->style();
     BoxDecorationData boxDecorationData(*style);
     BackgroundBleedAvoidance bleedAvoidance = determineBackgroundBleedAvoidance(paintInfo.context, boxDecorationData);
 
     // FIXME: Should eventually give the theme control over whether the box shadow should paint, since controls could have
     // custom shadows of their own.
@@ skipping 2047 matching lines @@
 
 RenderBox::BoxDecorationData::BoxDecorationData(const RenderStyle& style)
 {
     backgroundColor = style.colorIncludingFallback(CSSPropertyBackgroundColor);
     hasBackground = backgroundColor.alpha() || style.hasBackgroundImage();
     ASSERT(hasBackground == style.hasBackground());
     hasBorder = style.hasBorder();
 }
 
 } // namespace blink