Recompute percentage based @viewport on resize.

Source/core/css/CSSParser-in.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 1661 matching lines @@
         m_useCounter->count(propId);
 
     if (!m_valueList)
         return false;
 
     CSSParserValue* value = m_valueList->current();
 
     if (!value)
         return false;
 
+    if (inViewport()) {
+        if (!RuntimeEnabledFeatures::cssViewportEnabled())
+            return false;
+
+        return parseViewportProperty(propId, important);
+    }
+
     // Note: m_parsedCalculation is used to pass the calc value to validUnit and then cleared at the end of this function.
     // FIXME: This is to avoid having to pass parsedCalc to all validUnit callers.
     ASSERT(!m_parsedCalculation);
 
     CSSValueID id = value->id;
 
     int num = inShorthand() ? 1 : m_valueList->size();
 
     if (id == CSSValueInherit) {
         if (num != 1)
@@ skipping 17 matching lines @@
 
     if (isKeywordPropertyID(propId)) {
         if (!isValidKeywordPropertyAndValue(propId, id, m_context))
             return false;
         if (m_valueList->next() && !inShorthand())
             return false;
         addProperty(propId, cssValuePool().createIdentifierValue(id), important);
         return true;
     }
 
-    if (inViewport()) {
-        if (!RuntimeEnabledFeatures::cssViewportEnabled())
-            return false;
-
-        return parseViewportProperty(propId, important);
-    }
-
     bool validPrimitive = false;
     RefPtr<CSSValue> parsedValue;
 
     switch (propId) {
     case CSSPropertySize:                 // <length>{1,2} | auto | [ <page-size> || [ portrait | landscape] ]
         return parseSize(propId, important);
 
     case CSSPropertyQuotes:               // [<string> <string>]+ | none | inherit
         if (id)
             validPrimitive = true;
@@ skipping 10237 matching lines @@
 {
     // The tokenizer checks for the construct of an+b.
     // However, since the {ident} rule precedes the {nth} rule, some of those
     // tokens are identified as string literal. Furthermore we need to accept
     // "odd" and "even" which does not match to an+b.
     return equalIgnoringCase(token, "odd") || equalIgnoringCase(token, "even")
         || equalIgnoringCase(token, "n") || equalIgnoringCase(token, "-n");
 }
 
 }