Oilpan: make DocumentFragment a heap allocated object.

Source/core/editing/CompositeEditCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2007, 2008 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 1171 matching lines @@
     Position start = startOfParagraphToMove.deepEquivalent().downstream();
     Position end = endOfParagraphToMove.deepEquivalent().upstream();
 
     // start and end can't be used directly to create a Range; they are "editing positions"
     Position startRangeCompliant = start.parentAnchoredEquivalent();
     Position endRangeCompliant = end.parentAnchoredEquivalent();
     RefPtrWillBeRawPtr<Range> range = Range::create(document(), startRangeCompliant.deprecatedNode(), startRangeCompliant.deprecatedEditingOffset(), endRangeCompliant.deprecatedNode(), endRangeCompliant.deprecatedEditingOffset());
 
     // FIXME: This is an inefficient way to preserve style on nodes in the paragraph to move. It
     // shouldn't matter though, since moved paragraphs will usually be quite small.
-    RefPtr<DocumentFragment> fragment = startOfParagraphToMove != endOfParagraphToMove ?
+    RefPtrWillBeRawPtr<DocumentFragment> fragment = startOfParagraphToMove != endOfParagraphToMove ?
         createFragmentFromMarkup(document(), createMarkup(range.get(), 0, DoNotAnnotateForInterchange, true, DoNotResolveURLs, constrainingAncestor), "") : nullptr;
 
     // A non-empty paragraph's style is moved when we copy and move it.  We don't move
     // anything if we're given an empty paragraph, but an empty paragraph can have style
     // too, <div><b><br></b></div> for example.  Save it so that we can preserve it later.
     RefPtr<EditingStyle> styleInEmptyParagraph;
     if (startOfParagraphToMove == endOfParagraphToMove && preserveStyle) {
         styleInEmptyParagraph = EditingStyle::create(startOfParagraphToMove.deepEquivalent());
         styleInEmptyParagraph->mergeTypingStyle(&document());
         // The moved paragraph should assume the block style of the destination.
@@ skipping 265 matching lines @@
 
     return node.release();
 }
 
 PassRefPtrWillBeRawPtr<Element> createBlockPlaceholderElement(Document& document)
 {
     return document.createElement(brTag, false);
 }
 
 } // namespace WebCore