Updated ownership of NavigationItems within CRWSessionController.

ios/web/navigation/navigation_item_impl_list.mm

 // Copyright 2017 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/navigation/navigation_item_impl_list.h"
 
 #import "ios/web/navigation/navigation_item_impl.h"
 
 namespace web {
 
 ScopedNavigationItemImplList CreateScopedNavigationItemImplList(
     ScopedNavigationItemList scoped_item_list) {
   ScopedNavigationItemImplList list(scoped_item_list.size());
   for (size_t index = 0; index < scoped_item_list.size(); ++index) {
     std::unique_ptr<NavigationItemImpl> scoped_item_impl(
         static_cast<NavigationItemImpl*>(scoped_item_list[index].release()));
     list[index] = std::move(scoped_item_impl);
   }
   return list;
 }
 
+NavigationItemList CreateNavigationItemList(
+    ScopedNavigationItemImplList& scoped_item_list) {
+  NavigationItemList list(scoped_item_list.size());
+  for (size_t index = 0; index < scoped_item_list.size(); ++index) {
+    list[index] = scoped_item_list[index].get();
+  }
+  return list;
+}
+
 }  // namespace web