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

chrome/browser/tab_contents/render_view_host_manager.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/browser/tab_contents/render_view_host_manager.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "chrome/browser/dom_ui/dom_ui.h"
 #include "chrome/browser/dom_ui/dom_ui_factory.h"
@@ skipping 292 matching lines @@
   // We can't switch a RenderView between view source and non-view source mode
   // without screwing up the session history sometimes (when navigating between
   // "view-source:http://foo.com/" and "http://foo.com/", WebKit doesn't treat
   // it as a new navigation). So require a view switch.
   if (cur_entry->IsViewSourceMode() != new_entry->IsViewSourceMode())
     return true;
 
   // For security, we should transition between processes when one is a DOM UI
   // page and one isn't.
   Profile* profile = delegate_->GetControllerForRenderManager().profile();
-  if (DOMUIFactory::UseDOMUIForURL(profile, cur_entry->url()) !=
-      DOMUIFactory::UseDOMUIForURL(profile, new_entry->url()))
-    return true;
+  if (DOMUIFactory::UseDOMUIForURL(profile, cur_entry->url())) {
+    // Force swap if it's not an acceptable URL for DOM UI.
+    if (!DOMUIFactory::IsURLAcceptableForDOMUI(profile, new_entry->url()))
+      return true;
+  } else {
+    // Force swap if it's a DOM UI URL.
+    if (DOMUIFactory::UseDOMUIForURL(profile, new_entry->url()))
+      return true;
+  }
 
   // Also, we must switch if one is an extension and the other is not the exact
   // same extension.
   if (cur_entry->url().SchemeIs(chrome::kExtensionScheme) ||
       new_entry->url().SchemeIs(chrome::kExtensionScheme)) {
     if (cur_entry->url().GetOrigin() != new_entry->url().GetOrigin())
       return true;
   }
 
   return false;
@@ skipping 336 matching lines @@
   // deleted (not sure from where) but not NULLed.
   if (rvh == pending_render_view_host_) {
     // If you hit this NOTREACHED, please report it in the following bug
     // http://crbug.com/23411 Make sure to include what you were doing when it
     // happened  (navigating to a new page, closing a tab...) and if you can
     // reproduce.
     NOTREACHED();
     pending_render_view_host_ = NULL;
   }
 }