Recompute percentage based @viewport on resize.

Source/core/css/CSSParser-in.cpp

Index: Source/core/css/CSSParser-in.cpp
diff --git a/Source/core/css/CSSParser-in.cpp b/Source/core/css/CSSParser-in.cpp
index 8907000f6087060f6bb068e600e091bfa4c0c538..a6fada511198fc1d19af6e55abf927e0b1442191 100644
--- a/Source/core/css/CSSParser-in.cpp
+++ b/Source/core/css/CSSParser-in.cpp
@@ -1679,6 +1679,13 @@ bool CSSParser::parseValue(CSSPropertyID propId, bool important)
     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);
@@ -1716,13 +1723,6 @@ bool CSSParser::parseValue(CSSPropertyID propId, bool important)
         return true;
     }
 
-    if (inViewport()) {
-        if (!RuntimeEnabledFeatures::cssViewportEnabled())
-            return false;
-
-        return parseViewportProperty(propId, important);
-    }
-
     bool validPrimitive = false;
     RefPtr<CSSValue> parsedValue;