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

Source/core/loader/DocumentLoader.cpp

Index: Source/core/loader/DocumentLoader.cpp
diff --git a/Source/core/loader/DocumentLoader.cpp b/Source/core/loader/DocumentLoader.cpp
index 7957ac3794663a30fd0be8abac5115158507d4fd..1f585427fdbef4e693d3eb84e673322223bbf40c 100644
--- a/Source/core/loader/DocumentLoader.cpp
+++ b/Source/core/loader/DocumentLoader.cpp
@@ -774,7 +774,7 @@ void DocumentLoader::endWriting(DocumentWriter* writer)
     m_writer.clear();
 }
 
-PassRefPtr<DocumentWriter> DocumentLoader::createWriterFor(LocalFrame* frame, const Document* ownerDocument, const KURL& url, const AtomicString& mimeType, const AtomicString& encoding, bool userChosen, bool dispatch)
+PassRefPtrWillBeRawPtr<DocumentWriter> DocumentLoader::createWriterFor(LocalFrame* frame, const Document* ownerDocument, const KURL& url, const AtomicString& mimeType, const AtomicString& encoding, bool userChosen, bool dispatch)
 {
     // Create a new document before clearing the frame, because it may need to
     // inherit an aliased security context.
@@ -798,7 +798,7 @@ PassRefPtr<DocumentWriter> DocumentLoader::createWriterFor(LocalFrame* frame, co
     if (!shouldReuseDefaultView)
         frame->setDOMWindow(DOMWindow::create(*frame));
 
-    RefPtr<Document> document = frame->domWindow()->installNewDocument(mimeType, init);
+    RefPtrWillBeRawPtr<Document> document = frame->domWindow()->installNewDocument(mimeType, init);
     if (ownerDocument) {
         document->setCookieURL(ownerDocument->cookieURL());
         document->setSecurityOrigin(ownerDocument->securityOrigin());