Refactor serialisation of openerId & openerNavigationIndex.

ios/web/navigation/crw_session_controller+private_constructors.h

 // Copyright 2014 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_PRIVATE_CONSTRUCTORS_H_
 #define IOS_WEB_NAVIGATION_CRW_SESSION_CONTROLLER_PRIVATE_CONSTRUCTORS_H_
 
 #include <memory>
 #include <vector>
 
 #import "ios/web/navigation/crw_session_controller.h"
 #include "ios/web/public/navigation_item_list.h"
 
 namespace web {
 class BrowserState;
 class NavigationItem;
 }
 
 // Temporary interface for NavigationManager and tests to create
 // CRWSessionControllers. Once CRWSessionController has no users outside of
 // web/, these methods can go back into session_controller.h. crbug.com/318974
 @interface CRWSessionController (PrivateConstructors)
 // Initializes a session controller, supplying a unique textual identifier for
-// the window, or nil. |opener| is the tab id of the parent tab. It may be
-// nil or empty if there is no parent.
-- (id)initWithWindowName:(NSString*)windowName
-                openerId:(NSString*)opener
-             openedByDOM:(BOOL)openedByDOM
-   openerNavigationIndex:(NSInteger)openerIndex
-            browserState:(web::BrowserState*)browserState;
+// the window, or nil.
+- (instancetype)initWithWindowName:(NSString*)windowName
+                       openedByDOM:(BOOL)openedByDOM
+                      browserState:(web::BrowserState*)browserState;
 
 // Initializes a session controller, supplying a list of NavigationItem objects
 // and the current index in the navigation history.
-- (id)initWithNavigationItems:(web::ScopedNavigationItemList)items
-                 currentIndex:(NSUInteger)currentIndex
-                 browserState:(web::BrowserState*)browserState;
+- (instancetype)initWithNavigationItems:(web::ScopedNavigationItemList)items
+                           currentIndex:(NSUInteger)currentIndex
+                           browserState:(web::BrowserState*)browserState;
 @end
 
 #endif  // IOS_WEB_NAVIGATION_CRW_SESSION_CONTROLLER_PRIVATE_CONSTRUCTORS_H_