Introduce DEFINE_DOCUMENT_TYPE_CASTS, and use it

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 1329 matching lines @@
 }
 
 inline const Document* toDocument(const ExecutionContext* executionContext)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!executionContext || executionContext->isDocument());
     return static_cast<const Document*>(executionContext);
 }
 
 DEFINE_NODE_TYPE_CASTS(Document, isDocumentNode());
 
+#define DEFINE_DOCUMENT_TYPE_CASTS(thisType) \
+    DEFINE_TYPE_CASTS(thisType, Document, document, document->is##thisType(), document.is##thisType())
+
 // All these varations are needed to avoid ambiguous overloads with the Node and TreeScope versions.
 inline bool operator==(const Document& a, const Document& b) { return &a == &b; }
 inline bool operator==(const Document& a, const Document* b) { return &a == b; }
 inline bool operator==(const Document* a, const Document& b) { return a == &b; }
 inline bool operator!=(const Document& a, const Document& b) { return !(a == b); }
 inline bool operator!=(const Document& a, const Document* b) { return !(a == b); }
 inline bool operator!=(const Document* a, const Document& b) { return !(a == b); }
 
 // Put these methods here, because they require the Document definition, but we really want to inline them.
 
 inline bool Node::isDocumentNode() const
 {
     return this == documentInternal();
 }
 
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace WebCore
 
 #endif // Document_h