Change various helper classes to transition types to get CSSValue entirely onto the gc heap.

Source/core/css/MediaQueryExp.cpp

 /*
  * CSS Media Query
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 2013 Apple 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:
@@ skipping 177 matching lines @@
         || m_mediaFeature == MediaFeatureNames::maxWidthMediaFeature
         || m_mediaFeature == MediaFeatureNames::maxHeightMediaFeature
         || m_mediaFeature == MediaFeatureNames::orientationMediaFeature
         || m_mediaFeature == MediaFeatureNames::aspectRatioMediaFeature
         || m_mediaFeature == MediaFeatureNames::minAspectRatioMediaFeature
         || m_mediaFeature == MediaFeatureNames::devicePixelRatioMediaFeature
         || m_mediaFeature == MediaFeatureNames::resolutionMediaFeature
         || m_mediaFeature == MediaFeatureNames::maxAspectRatioMediaFeature;
 }
 
+MediaQueryExp::MediaQueryExp(const MediaQueryExp& other)
+    : m_mediaFeature(other.mediaFeature())
+    , m_value(other.value())
+{
+}
+
 MediaQueryExp::MediaQueryExp(const AtomicString& mediaFeature, PassRefPtrWillBeRawPtr<CSSValue> value)
     : m_mediaFeature(mediaFeature)
     , m_value(value)
 {
 }
 
-PassOwnPtr<MediaQueryExp> MediaQueryExp::create(const AtomicString& mediaFeature, CSSParserValueList* valueList)
+PassOwnPtrWillBeRawPtr<MediaQueryExp> MediaQueryExp::create(const AtomicString& mediaFeature, CSSParserValueList* valueList)
 {
     RefPtrWillBeRawPtr<CSSValue> cssValue;
     bool isValid = false;
 
     // Create value for media query expression that must have 1 or more values.
     if (valueList) {
         if (valueList->size() == 1) {
             CSSParserValue* value = valueList->current();
 
             if (featureWithCSSValueID(mediaFeature, value)) {
@@ skipping 46 matching lines @@
             if (isValid)
                 cssValue = CSSAspectRatioValue::create(numeratorValue, denominatorValue);
         }
     } else if (featureWithoutValue(mediaFeature)) {
         isValid = true;
     }
 
     if (!isValid)
         return nullptr;
 
-    return adoptPtr(new MediaQueryExp(mediaFeature, cssValue));
+    return adoptPtrWillBeNoop(new MediaQueryExp(mediaFeature, cssValue));
 }
 
 MediaQueryExp::~MediaQueryExp()
 {
 }
 
 String MediaQueryExp::serialize() const
 {
     StringBuilder result;
     result.append("(");
     result.append(m_mediaFeature.lower());
     if (m_value) {
         result.append(": ");
         result.append(m_value->cssText());
     }
     result.append(")");
 
     return result.toString();
 }
 
 } // namespace