Converted CRWSessionController to use NavigationItems.

ios/web/navigation/navigation_item_impl_list.h

+// 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.
+
+#ifndef IOS_WEB_NAVIGATION_NAVIGATION_ITEM_IMPL_LIST_H_
+#define IOS_WEB_NAVIGATION_NAVIGATION_ITEM_IMPL_LIST_H_
+
+#import "ios/web/public/navigation_item_list.h"
+
+namespace web {
+
+class NavigationItemImpl;
+
+// Convenience typedef for a list of raw NavigationItem pointers.
+typedef std::vector<NavigationItemImpl*> NavigationItemImplList;
+
+// Convenience typedef for a list of scoped NavigationItem pointers.
+typedef std::vector<std::unique_ptr<NavigationItemImpl>>
+    ScopedNavigationItemImplList;
+
+// Creates a ScopedNavigationItemImplList from |scoped_item_list|.  Ownership
+// of the NavigationItems in |scoped_item_list| is transferred to the returned
+// value.
+ScopedNavigationItemImplList CreateScopedNavigationItemImplList(
+    ScopedNavigationItemList scoped_item_list);
+
+}  // namespace web
+
+#endif  // IOS_WEB_NAVIGATION_NAVIGATION_ITEM_IMPL_LIST_H_