Adds NavigationManager util functions to ios/chrome/browser/web/

ios/web/navigation/crw_session_controller.h

 // Copyright 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 IOS_WEB_NAVIGATION_CRW_SESSION_CONTROLLER_H_
 #define IOS_WEB_NAVIGATION_CRW_SESSION_CONTROLLER_H_
 
 #import <Foundation/Foundation.h>
 #include <vector>
 
@@ skipping 50 matching lines @@
 // been received.
 @property(nonatomic, readonly) web::NavigationItemImpl* pendingItem;
 // Returns the transient NavigationItem, if any.  The transient item will be
 // discarded on any navigation, and is used to represent interstitials in the
 // session history.
 @property(nonatomic, readonly) web::NavigationItemImpl* transientItem;
 // Returns the NavigationItem corresponding with the last committed load.
 @property(nonatomic, readonly) web::NavigationItemImpl* lastCommittedItem;
 // Returns the NavigationItem corresponding with the previously loaded page.
 @property(nonatomic, readonly) web::NavigationItemImpl* previousItem;
-// Returns most recent NavigationItem that is not a redirect. Returns nil if
-// |items| is empty.
-@property(nonatomic, readonly) web::NavigationItemImpl* lastUserItem;
 // Returns a list of all non-redirected NavigationItems whose index precedes
 // |currentNavigationIndex|.
 @property(nonatomic, readonly) web::NavigationItemList backwardItems;
 // Returns a list of all non-redirected NavigationItems whose index follow
 // |currentNavigationIndex|.
 @property(nonatomic, readonly) web::NavigationItemList forwardItems;
 
 // CRWSessionController doesn't have public constructors. New
 // CRWSessionControllers are created by deserialization, or via a
 // NavigationManager.
@@ skipping 70 matching lines @@
 
 // Returns the index of |item| in |items|.
 - (NSInteger)indexOfItem:(const web::NavigationItem*)item;
 
 // Returns the item at |index| in |items|.
 - (web::NavigationItemImpl*)itemAtIndex:(NSInteger)index;
 
 @end
 
 #endif  // IOS_WEB_NAVIGATION_CRW_SESSION_CONTROLLER_H_