Node.prototype.baseURI should not be nullable

third_party/WebKit/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)
@@ skipping 591 matching lines @@
   // Return the document URL, or an empty URL if it's unavailable.
   // This is not an implementation of web-exposed Document.prototype.URL.
   const KURL& Url() const { return url_; }
   void SetURL(const KURL&);
 
   // Bind the url to document.url, if unavailable bind to about:blank.
   KURL urlForBinding();
 
   // To understand how these concepts relate to one another, please see the
   // comments surrounding their declaration.
-  const KURL& BaseURL() const { return base_url_; }
+  const KURL& BaseURL() const;
   void SetBaseURLOverride(const KURL&);
   const KURL& BaseURLOverride() const { return base_url_override_; }
   KURL ValidBaseElementURL() const;
   const AtomicString& BaseTarget() const { return base_target_; }
   void ProcessBaseElement();
 
   // Creates URL based on passed relative url and this documents base URL.
   // Depending on base URL value it is possible that parent document
   // base URL will be used instead. Uses completeURLWithOverride internally.
   KURL CompleteURL(const String&) const;
@@ skipping 1109 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif  // Document_h