Create a NavigationEntry for the initial blank page.

content/public/browser/navigation_type.h

 // Copyright (c) 2012 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 CONTENT_PUBLIC_BROWSER_NAVIGATION_TYPE_H_
 #define CONTENT_PUBLIC_BROWSER_NAVIGATION_TYPE_H_
 
 namespace content {
 
 // Indicates different types of navigations that can occur that we will handle
@@ skipping 27 matching lines @@
   // A subframe in the page was automatically loaded or navigated to such that
   // a new navigation entry should not be created. There are two cases:
   //  1. Stuff like iframes containing ads that the page loads automatically.
   //     The user doesn't want to see these, so we just update the existing
   //     navigation entry.
   //  2. Going back/forward to previous subframe navigations. We don't create
   //     a new entry here either, just update the last committed entry.
   // These two cases are actually pretty different, they just happen to
   // require almost the same code to handle.
   NAVIGATION_TYPE_AUTO_SUBFRAME,
-
-  // Nothing happened. This happens when we get information about a page we
-  // don't know anything about. It can also happen when an iframe in a popup
-  // navigated to about:blank is navigated. Nothing needs to be done.
-  NAVIGATION_TYPE_NAV_IGNORE,
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_NAVIGATION_TYPE_H_