Do not zero-initialize RawPtr.

Source/core/css/CSSCalculationValue.cpp

 /*
  * Copyright (C) 2011, 2012 Google 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:
  *
  *     * 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
@@ skipping 524 matching lines @@
 {
     (*depth)++;
     if (*depth > maxExpressionDepth)
         return TooDeep;
     if (index >= tokens->size())
         return NoMoreTokens;
     return OK;
 }
 
 class CSSCalcExpressionNodeParser {
-    DISALLOW_ALLOCATION(); // Is only ever stack allocated.
+    STACK_ALLOCATED();
 public:
     PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> parseCalc(CSSParserValueList* tokens)
     {
         unsigned index = 0;
         Value result;
         bool ok = parseValueExpression(tokens, 0, &index, &result);
         ASSERT_WITH_SECURITY_IMPLICATION(index <= tokens->size());
         if (!ok || index != tokens->size())
             return nullptr;
         return result.value;
     }
 
 private:
     struct Value {
-        DISALLOW_ALLOCATION(); // Is only ever stack allocated.
+        STACK_ALLOCATED();
     public:
-        RefPtrWillBeRawPtr<CSSCalcExpressionNode> value;
+        RefPtrWillBeMember<CSSCalcExpressionNode> value;
     };
 
     char operatorValue(CSSParserValueList* tokens, unsigned index)
     {
         if (index >= tokens->size())
             return 0;
         CSSParserValue* value = tokens->valueAt(index);
         if (value->unit != CSSParserValue::Operator)
             return 0;
 
@@ skipping 164 matching lines @@
         ASSERT_NOT_REACHED();
         return nullptr;
     }
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 PassRefPtrWillBeRawPtr<CSSCalcValue> CSSCalcValue::create(CSSParserString name, CSSParserValueList* parserValueList, ValueRange range)
 {
     CSSCalcExpressionNodeParser parser;
-    RefPtrWillBeRawPtr<CSSCalcExpressionNode> expression;
+    RefPtrWillBeRawPtr<CSSCalcExpressionNode> expression = nullptr;
 
     if (equalIgnoringCase(name, "calc(") || equalIgnoringCase(name, "-webkit-calc("))
         expression = parser.parseCalc(parserValueList);
     // FIXME calc (http://webkit.org/b/16662) Add parsing for min and max here
 
     return expression ? adoptRefWillBeRefCountedGarbageCollected(new CSSCalcValue(expression, range)) : nullptr;
 }
 
 PassRefPtrWillBeRawPtr<CSSCalcValue> CSSCalcValue::create(PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> expression, ValueRange range)
 {
     return adoptRefWillBeRefCountedGarbageCollected(new CSSCalcValue(expression, range));
 }
 
 void CSSCalcValue::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_expression);
     CSSValue::traceAfterDispatch(visitor);
 }
 
 } // namespace WebCore