Improve RAII of StyleResolverState.

Source/core/css/resolver/StyleBuilderConverter.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 207 matching lines @@
         return primitiveValue->cssCalcValue()->toCalcValue(conversionData)->evaluate(parentSize.value);
 
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 FontDescription::Size StyleBuilderConverter::convertFontSize(StyleResolverState& state, CSSValue* value)
 {
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
 
-    FontDescription::Size parentSize(0, 0.0f, false);
-
-    // FIXME: Find out when parentStyle could be 0?
-    if (state.parentStyle())
-        parentSize = state.parentFontDescription().size();
+    FontDescription::Size parentSize = state.parentFontDescription().size();
 
     if (CSSValueID valueID = primitiveValue->getValueID()) {
         switch (valueID) {
         case CSSValueXxSmall:
         case CSSValueXSmall:
         case CSSValueSmall:
         case CSSValueMedium:
         case CSSValueLarge:
         case CSSValueXLarge:
         case CSSValueXxLarge:
@@ skipping 576 matching lines @@
     CSSPrimitiveValue* primitiveValueZ = toCSSPrimitiveValue(list->item(2));
 
     return TransformOrigin(
         convertOriginLength<CSSValueLeft, CSSValueRight>(state, primitiveValueX),
         convertOriginLength<CSSValueTop, CSSValueBottom>(state, primitiveValueY),
         StyleBuilderConverter::convertComputedLength<float>(state, primitiveValueZ)
     );
 }
 
 } // namespace blink