Move MediaQuery classes off BlinkGC heap

third_party/WebKit/Source/core/html/HTMLSourceElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2010 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 57 matching lines @@
 
 HTMLSourceElement::~HTMLSourceElement() {}
 
 void HTMLSourceElement::createMediaQueryList(const AtomicString& media) {
   removeMediaQueryListListener();
   if (media.isEmpty()) {
     m_mediaQueryList = nullptr;
     return;
   }
 
-  MediaQuerySet* set = MediaQuerySet::create(media);
+  RefPtr<MediaQuerySet> set = MediaQuerySet::create(media);
   m_mediaQueryList =
       MediaQueryList::create(&document(), &document().mediaQueryMatcher(), set);
   addMediaQueryListListener();
 }
 
 void HTMLSourceElement::didMoveToNewDocument(Document& oldDocument) {
   createMediaQueryList(fastGetAttribute(mediaAttr));
   HTMLElement::didMoveToNewDocument(oldDocument);
 }
 
@@ skipping 95 matching lines @@
     toHTMLPictureElement(parent)->sourceOrMediaChanged();
 }
 
 DEFINE_TRACE(HTMLSourceElement) {
   visitor->trace(m_mediaQueryList);
   visitor->trace(m_listener);
   HTMLElement::trace(visitor);
 }
 
 }  // namespace blink