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()) {
     media_query_list_ = nullptr;
     return;
   }
 
-  MediaQuerySet* set = MediaQuerySet::Create(media);
+  RefPtr<MediaQuerySet> set = MediaQuerySet::Create(media);
   media_query_list_ = MediaQueryList::Create(
       &GetDocument(), &GetDocument().GetMediaQueryMatcher(), set);
   AddMediaQueryListListener();
 }
 
 void HTMLSourceElement::DidMoveToNewDocument(Document& old_document) {
   CreateMediaQueryList(FastGetAttribute(mediaAttr));
   HTMLElement::DidMoveToNewDocument(old_document);
 }
 
@@ skipping 96 matching lines @@
     toHTMLPictureElement(parent)->SourceOrMediaChanged();
 }
 
 DEFINE_TRACE(HTMLSourceElement) {
   visitor->Trace(media_query_list_);
   visitor->Trace(listener_);
   HTMLElement::Trace(visitor);
 }
 
 }  // namespace blink