Reduce risk of MediaQueryEvaluator-induced leaks.

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

 /*
  * CSS Media Query Evaluator
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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 74 matching lines @@
 MediaQueryEvaluator::MediaQueryEvaluator(const MediaValues& mediaValues)
     : m_expectedResult(false) // Doesn't matter when we have mediaValues.
     , m_mediaValues(mediaValues.copy())
 {
 }
 
 MediaQueryEvaluator::~MediaQueryEvaluator()
 {
 }
 
+DEFINE_TRACE(MediaQueryEvaluator)
+{
+    visitor->trace(m_mediaValues);
+}
+
 const String MediaQueryEvaluator::mediaType() const
 {
     // If a static mediaType was given by the constructor, we use it here.
     if (!m_mediaType.isEmpty())
         return m_mediaType;
     // Otherwise, we get one from mediaValues (which may be dynamic or cached).
     if (m_mediaValues)
         return m_mediaValues->mediaType();
     return nullAtom;
 }
@@ skipping 553 matching lines @@
     // Call the media feature evaluation function. Assume no prefix and let
     // trampoline functions override the prefix if prefix is used.
     EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());
     if (func)
         return func(expr->expValue(), NoPrefix, *m_mediaValues);
 
     return false;
 }
 
 } // namespace