Oilpan: add [WillBeGarbageCollected] for Node.

Source/core/dom/DOMImplementation.cpp

Index: Source/core/dom/DOMImplementation.cpp
diff --git a/Source/core/dom/DOMImplementation.cpp b/Source/core/dom/DOMImplementation.cpp
index 73d21fba7b8615cddffe20722dca085e8ea3c004..a8d7f1b2c17cb04f568377d5f140588ca66436b5 100644
--- a/Source/core/dom/DOMImplementation.cpp
+++ b/Source/core/dom/DOMImplementation.cpp
@@ -332,12 +332,12 @@ PassRefPtrWillBeRawPtr<HTMLDocument> DOMImplementation::createHTMLDocument(const
     return d.release();
 }
 
-PassRefPtr<Document> DOMImplementation::createDocument(const String& type, LocalFrame* frame, const KURL& url, bool inViewSourceMode)
+PassRefPtrWillBeRawPtr<Document> DOMImplementation::createDocument(const String& type, LocalFrame* frame, const KURL& url, bool inViewSourceMode)
 {
     return createDocument(type, DocumentInit(url, frame), inViewSourceMode);
 }
 
-PassRefPtr<Document> DOMImplementation::createDocument(const String& type, const DocumentInit& init, bool inViewSourceMode)
+PassRefPtrWillBeRawPtr<Document> DOMImplementation::createDocument(const String& type, const DocumentInit& init, bool inViewSourceMode)
 {
     if (inViewSourceMode)
         return HTMLViewSourceDocument::create(init, type);