Fixed title updating for back forward navigation.

ios/web/web_state/ui/crw_wk_navigation_states.mm

 // Copyright 2016 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.
 
 #import "ios/web/web_state/ui/crw_wk_navigation_states.h"
 
 #include "base/logging.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ skipping 87 matching lines @@
   for (WKNavigation* navigation in _records) {
     CRWWKNavigationsStateRecord* record = [_records objectForKey:navigation];
     if (lastAddedIndex < record.index) {
       result = navigation;
       lastAddedIndex = record.index;
     }
   }
   return result;
 }
 
+- (web::WKNavigationState)lastAddedNavigationState {
+  CRWWKNavigationsStateRecord* lastAddedRecord = nil;
+  WKNavigation* lastAddedNavigation = [self lastAddedNavigation];
+  if (lastAddedNavigation)
+    lastAddedRecord = [_records objectForKey:lastAddedNavigation];
+
+  return lastAddedRecord.state;
+}
+
 @end