Revert "Revert "Allow DOMUI pages to call window.open(), giving DOMUI privileges to the new""

chrome/browser/dom_ui/dom_ui_factory.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_DOM_UI_DOM_UI_FACTORY_H_
 #define CHROME_BROWSER_DOM_UI_DOM_UI_FACTORY_H_
 
 #include <vector>
 
 class DOMUI;
 class GURL;
 class TabContents;
 
+// An opaque identifier used to identify a DOMUI. This can only be compared to
+// kNoDOMUI or other DOMUI types. See GetDOMUIType.
+typedef void* DOMUITypeID;
+
 class DOMUIFactory {
  public:
+  // A special DOMUI type that signifies that a given page would not use the
+  // DOM UI system.
+  static const DOMUITypeID kNoDOMUI;
+
+  // Returns a type identifier indicating what DOMUI we would use for the
+  // given URL. This is useful for comparing the potential DOMUIs for two URLs.
+  // Returns kNoDOMUI if the given URL will not use the DOM UI system.
+  static DOMUITypeID GetDOMUIType(const GURL& url);
+
   // Returns true if the given URL's scheme would trigger the DOM UI system.
   // This is a less precise test than UseDONUIForURL, which tells you whether
   // that specific URL matches a known one. This one is faster and can be used
   // to determine security policy.
   static bool HasDOMUIScheme(const GURL& url);
 
   // Returns true if the given URL will use the DOM UI system.
   static bool UseDOMUIForURL(const GURL& url);
 
   // Allocates a new DOMUI object for the given URL, and returns it. If the URL
   // is not a DOM UI URL, then it will return NULL. When non-NULL, ownership of
   // the returned pointer is passed to the caller.
   static DOMUI* CreateDOMUIForURL(TabContents* tab_contents, const GURL& url);
 
   // Gets the data for the favicon for a DOMUI page. Returns false if the DOMUI
   // does not have a favicon.
   static bool GetFaviconResourceBytes(const GURL& page_url,
                                       std::vector<unsigned char>* bytes);
 
  private:
   // Class is for scoping only.
   DOMUIFactory() {};
 };
 
 #endif  // CHROME_BROWSER_DOM_UI_DOM_UI_FACTORY_H_