Oilpan: make DocumentFragment a heap allocated object.

Source/core/dom/shadow/ShadowRoot.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 108 matching lines @@
     return createMarkup(this, ChildrenOnly);
 }
 
 void ShadowRoot::setInnerHTML(const String& markup, ExceptionState& exceptionState)
 {
     if (isOrphan()) {
         exceptionState.throwDOMException(InvalidAccessError, "The ShadowRoot does not have a host.");
         return;
     }
 
-    if (RefPtr<DocumentFragment> fragment = createFragmentForInnerOuterHTML(markup, host(), AllowScriptingContent, "innerHTML", exceptionState))
+    if (RefPtrWillBeRawPtr<DocumentFragment> fragment = createFragmentForInnerOuterHTML(markup, host(), AllowScriptingContent, "innerHTML", exceptionState))
         replaceChildrenWithFragment(this, fragment.release(), exceptionState);
 }
 
 void ShadowRoot::recalcStyle(StyleRecalcChange change)
 {
     // ShadowRoot doesn't support custom callbacks.
     ASSERT(!hasCustomStyleCallbacks());
 
     StyleResolverParentScope parentScope(*this);
 
@@ skipping 199 matching lines @@
 void ShadowRoot::trace(Visitor* visitor)
 {
     visitor->trace(m_prev);
     visitor->trace(m_next);
     visitor->trace(m_shadowRootRareData);
     TreeScope::trace(visitor);
     DocumentFragment::trace(visitor);
 }
 
 }