Move viewport unit resolution to style recalc time

Source/core/css/resolver/MatchedPropertiesCache.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 91 matching lines @@
         cacheItem->clear();
 
     cacheItem->set(style, parentStyle, matchResult);
 }
 
 void MatchedPropertiesCache::clear()
 {
     m_cache.clear();
 }
 
+void MatchedPropertiesCache::clearViewportDependent()
+{
+    Vector<unsigned, 16> toRemove;
+    for (Cache::iterator it = m_cache.begin(); it != m_cache.end(); ++it) {
+        CachedMatchedProperties* cacheItem = it->value.get();
+        if (cacheItem->renderStyle->hasViewportUnits())
+            toRemove.append(it->key);
+    }
+    for (size_t i = 0; i < toRemove.size(); ++i)
+        m_cache.remove(toRemove[i]);
+}
+
 void MatchedPropertiesCache::sweep(Timer<MatchedPropertiesCache>*)
 {
     // Look for cache entries containing a style declaration with a single ref and remove them.
     // This may happen when an element attribute mutation causes it to generate a new inlineStyle()
     // or presentationAttributeStyle(), potentially leaving this cache with the last ref on the old one.
     Vector<unsigned, 16> toRemove;
     Cache::iterator it = m_cache.begin();
     Cache::iterator end = m_cache.end();
     for (; it != end; ++it) {
         CachedMatchedProperties* cacheItem = it->value.get();
@@ skipping 29 matching lines @@
     // CSSPropertyInternalCallback sets the rule's selector name into the RenderStyle, and that's not recalculated if the RenderStyle is loaded from the cache, so don't cache it.
     if (!style->callbackSelectors().isEmpty())
         return false;
     // The cache assumes static knowledge about which properties are inherited.
     if (parentStyle->hasExplicitlyInheritedProperties())
         return false;
     return true;
 }
 
 }