[Oilpan]: Make StylePropertySet fully garbage collected.

Source/core/css/parser/SizesCalcParserTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/css/parser/SizesCalcParser.h"
 
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/MediaValuesCached.h"
 #include "core/css/StylePropertySet.h"
@@ skipping 14 matching lines @@
 {
     lengthArray.resize(CSSPrimitiveValue::LengthUnitTypeCount);
     for (size_t i = 0; i < CSSPrimitiveValue::LengthUnitTypeCount; ++i)
         lengthArray.at(i) = 0;
 }
 
 static void verifyCSSCalc(String text, double value, bool valid, unsigned fontSize, unsigned viewportWidth, unsigned viewportHeight)
 {
     CSSLengthArray lengthArray;
     initLengthArray(lengthArray);
-    RefPtr<MutableStylePropertySet> propertySet = MutableStylePropertySet::create();
+    RefPtrWillBeRawPtr<MutableStylePropertySet> propertySet = MutableStylePropertySet::create();
     propertySet->setProperty(CSSPropertyLeft, text);
     RefPtrWillBeRawPtr<CSSValue> cssValue = propertySet->getPropertyCSSValue(CSSPropertyLeft);
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(cssValue.get());
     if (primitiveValue)
         primitiveValue->accumulateLengthArray(lengthArray);
     else
         ASSERT_EQ(valid, false);
     int length = lengthArray.at(CSSPrimitiveValue::UnitTypePixels);
     length += lengthArray.at(CSSPrimitiveValue::UnitTypeFontSize) * fontSize;
     length += lengthArray.at(CSSPrimitiveValue::UnitTypeViewportWidth) * viewportWidth / 100.0;
@@ skipping 81 matching lines @@
     }
 
     for (unsigned i = 0; testCases[i].input; ++i) {
         if (testCases[i].dontRunInCSSCalc)
             continue;
         verifyCSSCalc(testCases[i].input, testCases[i].output, testCases[i].valid, data.defaultFontSize, data.viewportWidth, data.viewportHeight);
     }
 }
 
 } // namespace