Oilpan: Replace RefPtrs to Node and its subclasses in core/xml/ with Oilpan transition types.

Source/core/dom/DOMImplementation.h

Index: Source/core/dom/DOMImplementation.h
diff --git a/Source/core/dom/DOMImplementation.h b/Source/core/dom/DOMImplementation.h
index 90d416304d767da28946a5a995726b8b8cc9238c..207d2c62ce5c505d7962208d974fa3cac7596f2f 100644
--- a/Source/core/dom/DOMImplementation.h
+++ b/Source/core/dom/DOMImplementation.h
@@ -64,8 +64,8 @@ public:
     PassRefPtrWillBeRawPtr<HTMLDocument> createHTMLDocument(const String& title);
 
     // Other methods (not part of DOM)
-    static PassRefPtr<Document> createDocument(const String& mimeType, LocalFrame*, const KURL&, bool inViewSourceMode);
-    static PassRefPtr<Document> createDocument(const String& mimeType, const DocumentInit&, bool inViewSourceMode);
+    static PassRefPtrWillBeRawPtr<Document> createDocument(const String& mimeType, LocalFrame*, const KURL&, bool inViewSourceMode);
+    static PassRefPtrWillBeRawPtr<Document> createDocument(const String& mimeType, const DocumentInit&, bool inViewSourceMode);
 
     static bool isXMLMIMEType(const String&);
     static bool isTextMIMEType(const String&);