Move viewport unit resolution to style recalc time

Source/core/dom/TreeScope.cpp

 /*
  * Copyright (C) 2011 Google Inc. All Rights Reserved.
  * Copyright (C) 2012 Apple Inc. 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.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 479 matching lines @@
         if (equalIgnoringCase(element->fastGetAttribute(accesskeyAttr), key))
             result = element;
         for (ShadowRoot* shadowRoot = element->youngestShadowRoot(); shadowRoot; shadowRoot = shadowRoot->olderShadowRoot()) {
             if (Element* shadowResult = shadowRoot->getElementByAccessKey(key))
                 result = shadowResult;
         }
     }
     return result;
 }
 
+void TreeScope::setNeedsStyleRecalcForViewportUnits()
+{
+    for (Element* element = ElementTraversal::firstWithin(*rootNode()); element; element = ElementTraversal::nextIncludingPseudo(*element)) {
+        for (ShadowRoot* root = element->youngestShadowRoot(); root; root = root->olderShadowRoot())
+            root->setNeedsStyleRecalcForViewportUnits();
+        RenderStyle* style = element->renderStyle();
+        if (style && style->hasViewportUnits())
+            element->setNeedsStyleRecalc(LocalStyleChange);
+    }
+}
+
 } // namespace WebCore