Implement lazy block layout prototype behind a runtime flag.

Source/core/css/StyleResolver.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 1463 matching lines @@
 }
 
 static EDisplay equivalentBlockDisplay(EDisplay display, bool isFloating, bool strictParsing)
 {
     switch (display) {
     case BLOCK:
     case TABLE:
     case BOX:
     case FLEX:
     case GRID:
+    case LAZY_BLOCK:
         return display;
 
     case LIST_ITEM:
         // It is a WinIE bug that floated list items lose their bullets, so we'll emulate the quirk, but only in quirks mode.
         if (!strictParsing && isFloating)
             return BLOCK;
         return display;
     case INLINE_TABLE:
         return TABLE;
     case INLINE_BOX:
@@ skipping 3149 matching lines @@
     info.addMember(m_state, "state");
 
     // FIXME: move this to a place where it would be called only once?
     info.addMember(CSSDefaultStyleSheets::defaultStyle, "defaultStyle");
     info.addMember(CSSDefaultStyleSheets::defaultQuirksStyle, "defaultQuirksStyle");
     info.addMember(CSSDefaultStyleSheets::defaultPrintStyle,"defaultPrintStyle");
     info.addMember(CSSDefaultStyleSheets::defaultViewSourceStyle, "defaultViewSourceStyle");
 }
 
 } // namespace WebCore