Implement Paint Containment

third_party/WebKit/Source/core/layout/LayoutBox.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 86 matching lines @@
 {
     setIsBox();
 }
 
 PaintLayerType LayoutBox::layerTypeRequired() const
 {
     // hasAutoZIndex only returns true if the element is positioned or a flex-item since
     // position:static elements that are not flex-items get their z-index coerced to auto.
     if (isPositioned() || createsGroup() || hasClipPath() || hasTransformRelatedProperty()
         || style()->hasCompositorProxy() || hasHiddenBackface() || hasReflection() || style()->specifiesColumns()
         || !style()->hasAutoZIndex() || style()->shouldCompositeForCurrentAnimations())

[chrishtr, 2015/12/09 01:41:46]

!hasAutoZIndex should be enough, line 110 will be a no-op.

[leviw_travelin_and_unemployed, 2015/12/09 21:09:24]

Good point :)

         return NormalPaintLayer;
 
-    if (hasOverflowClip())
+    if (hasOverflowClip() || style()->containsPaint())
         return OverflowClipPaintLayer;
 
     return NoPaintLayer;
 }
 
 void LayoutBox::willBeDestroyed()
 {
     clearOverrideSize();
     clearContainingBlockOverrideSize();
     clearExtraInlineAndBlockOffests();
@@ skipping 4718 matching lines @@
     StyleImage* borderImage = style()->borderImage().image();
     return borderImage && borderImage->canRender() && borderImage->isLoaded();
 }
 
 ShapeOutsideInfo* LayoutBox::shapeOutsideInfo() const
 {
     return ShapeOutsideInfo::isEnabledFor(*this) ? ShapeOutsideInfo::info(*this) : nullptr;
 }
 
 } // namespace blink