Prevent a crash when visiting about:hang in two NTPs.

chrome/browser/dom_ui/dom_ui_factory.h

Index: chrome/browser/dom_ui/dom_ui_factory.h
diff --git a/chrome/browser/dom_ui/dom_ui_factory.h b/chrome/browser/dom_ui/dom_ui_factory.h
index 3a7bfc683d949fa4c6ceb2f31d64310b3e9a1942..1e1ed871ae270f5d546c161c036bb681206a5c7d 100644
--- a/chrome/browser/dom_ui/dom_ui_factory.h
+++ b/chrome/browser/dom_ui/dom_ui_factory.h
@@ -35,9 +35,14 @@ class DOMUIFactory {
   // to determine security policy.
   static bool HasDOMUIScheme(const GURL& url);
 
-  // Returns true if the given URL will use the DOM UI system.
+  // Returns true if the given URL must use the DOM UI system.
   static bool UseDOMUIForURL(Profile* profile, const GURL& url);
 
+  // Returns true if the given URL can be loaded by DOM UI system.  This
+  // includes URLs that can be loaded by normal tabs as well, such as
+  // javascript: URLs or about:hang.
+  static bool IsURLAcceptableForDOMUI(Profile* profile, 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.