Reduce risk of MediaQueryEvaluator-induced leaks.

third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 132 matching lines @@
 StyleResolver::StyleResolver(Document& document)
     : m_document(document)
     , m_viewportStyleResolver(ViewportStyleResolver::create(&document))
     , m_needCollectFeatures(false)
     , m_printMediaType(false)
     , m_styleSharingDepth(0)
     , m_accessCount(0)
 {
     FrameView* view = document.view();
     if (view) {
-        m_medium = adoptPtr(new MediaQueryEvaluator(&view->frame()));
+        m_medium = adoptPtrWillBeNoop(new MediaQueryEvaluator(&view->frame()));
         m_printMediaType = equalIgnoringCase(view->mediaType(), MediaTypeNames::print);
     } else {
-        m_medium = adoptPtr(new MediaQueryEvaluator("all"));
+        m_medium = adoptPtrWillBeNoop(new MediaQueryEvaluator("all"));
     }
 
     initWatchedSelectorRules();
 }
 
 StyleResolver::~StyleResolver()
 {
 }
 
 void StyleResolver::dispose()
@@ skipping 1374 matching lines @@
         if (m_medium->eval(m_viewportDependentMediaQueryResults[i]->expression()) != m_viewportDependentMediaQueryResults[i]->result())
             return true;
     }
     return false;
 }
 
 DEFINE_TRACE(StyleResolver)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_matchedPropertiesCache);
+    visitor->trace(m_medium);
     visitor->trace(m_viewportDependentMediaQueryResults);
     visitor->trace(m_selectorFilter);
     visitor->trace(m_viewportStyleResolver);
     visitor->trace(m_features);
     visitor->trace(m_siblingRuleSet);
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingScopes);
     visitor->trace(m_styleSharingLists);
     visitor->trace(m_pendingStyleSheets);
     visitor->trace(m_document);
 #endif
 }
 
 } // namespace blink