Reduce risk of MediaQueryEvaluator-induced leaks.

third_party/WebKit/Source/core/css/MediaQueryEvaluator.h

 /*
  * CSS Media Query Evaluator
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 35 matching lines @@
 // CSS3 Module "Media Queries" (http://www.w3.org/TR/css3-mediaqueries/)
 // Special constructors are needed, if simple media queries are to be
 // evaluated without knowledge of the medium features. This can happen
 // for example when parsing UA stylesheets, if evaluation is done
 // right after parsing.
 //
 // the boolean parameter is used to approximate results of evaluation, if
 // the device characteristics are not known. This can be used to prune the loading
 // of stylesheets to only those which are probable to match.
 
-class CORE_EXPORT MediaQueryEvaluator {
-    WTF_MAKE_NONCOPYABLE(MediaQueryEvaluator); USING_FAST_MALLOC(MediaQueryEvaluator);
+class CORE_EXPORT MediaQueryEvaluator final : public NoBaseWillBeGarbageCollectedFinalized<MediaQueryEvaluator> {
+    WTF_MAKE_NONCOPYABLE(MediaQueryEvaluator);
+    USING_FAST_MALLOC_WILL_BE_REMOVED(MediaQueryEvaluator);
 public:
     // Creates evaluator which evaluates only simple media queries
     // Evaluator returns true for "all", and returns value of \mediaFeatureResult
     // for any media features.
 
     explicit MediaQueryEvaluator(bool mediaFeatureResult = false);
 
     // Creates evaluator which evaluates only simple media queries
     // Evaluator  returns true for acceptedMediaType and returns value of \mediafeatureResult
     // for any media features.
@@ skipping 12 matching lines @@
 
     // Evaluates a list of media queries.
     bool eval(const MediaQuerySet*, MediaQueryResultList* = 0) const;
 
     // Evaluates media query.
     bool eval(const MediaQuery*, MediaQueryResultList*) const;
 
     // Evaluates media query subexpression, ie "and (media-feature: value)" part.
     bool eval(const MediaQueryExp*) const;
 
+    DECLARE_TRACE();
+
 private:
     const String mediaType() const;
 
     String m_mediaType;
     bool m_expectedResult;
-    RefPtrWillBePersistent<MediaValues> m_mediaValues;
+    RefPtrWillBeMember<MediaValues> m_mediaValues;
 };
 
 } // namespace
 #endif