Remove the concept of document.documentElement

sky/engine/core/css/resolver/StyleAdjuster.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 115 matching lines @@
         }
     }
     return false;
 }
 
 void StyleAdjuster::adjustRenderStyle(RenderStyle* style, RenderStyle* parentStyle, Element& element)
 {
     ASSERT(parentStyle);
 
     if (style->display() != NONE) {
-        // Absolute/fixed positioned elements, floating elements and the document element need block-like outside display.
-        if (style->hasOutOfFlowPosition() || element.document().documentElement() == element)
-            style->setDisplay(equivalentBlockDisplay(style->display()));
-
-        if (parentStyle->requiresOnlyBlockChildren())
+        if (style->hasOutOfFlowPosition() || parentStyle->requiresOnlyBlockChildren())
             style->setDisplay(equivalentBlockDisplay(style->display()));
         else
             style->setDisplay(equivalentInlineDisplay(style->display()));
     }
 
     // Make sure our z-index value is only applied if the object is positioned.
     if (style->position() == StaticPosition && !parentStyleForcesZIndexToCreateStackingContext(parentStyle))
         style->setHasAutoZIndex();
 
-    // Auto z-index becomes 0 for the root element and transparent objects. This prevents
-    // cases where objects that should be blended as a single unit end up with a non-transparent
-    // object wedged in between them. Auto z-index also becomes 0 for objects that specify transforms.
-    if (style->hasAutoZIndex() && ((element.document().documentElement() == element)
-        || style->hasOpacity()
-        || style->hasTransformRelatedProperty()
-        || style->clipPath()
-        || style->hasFilter()
-        || hasWillChangeThatCreatesStackingContext(style)))
+    if (style->hasAutoZIndex()
+        && (style->hasOpacity()
+            || style->hasTransformRelatedProperty()
+            || style->clipPath()
+            || style->hasFilter()
+            || hasWillChangeThatCreatesStackingContext(style)))
         style->setZIndex(0);
 
     // will-change:transform should result in the same rendering behavior as having a transform,
     // including the creation of a containing block for fixed position descendants.
     if (!style->hasTransform() && (style->willChangeProperties().contains(CSSPropertyWebkitTransform) || style->willChangeProperties().contains(CSSPropertyTransform))) {
         bool makeIdentity = true;
         style->setTransform(TransformOperations(makeIdentity));
     }
 
     if (doesNotInheritTextDecoration(style, element))
@@ skipping 81 matching lines @@
         // FIXME: Once we implement pagination controls, overflow-x should default to hidden
         // if overflow-y is set to -webkit-paged-x or -webkit-page-y. For now, we'll let it
         // default to auto so we can at least scroll through the pages.
         style->setOverflowX(OAUTO);
     } else if (style->overflowY() == OVISIBLE && style->overflowX() != OVISIBLE) {
         style->setOverflowY(OAUTO);
     }
 }
 
 }