Refactor serialisation of openerId & openerNavigationIndex.

ios/web/navigation/navigation_manager_impl.mm

Index: ios/web/navigation/navigation_manager_impl.mm
diff --git a/ios/web/navigation/navigation_manager_impl.mm b/ios/web/navigation/navigation_manager_impl.mm
index bb16cba464bb1a3689eeca3a77fd606ca20e5cfe..9eb0475d298bb69cd595b562e1c31c425b928f58 100644
--- a/ios/web/navigation/navigation_manager_impl.mm
+++ b/ios/web/navigation/navigation_manager_impl.mm
@@ -95,14 +95,10 @@ void NavigationManagerImpl::SetSessionController(
 }
 
 void NavigationManagerImpl::InitializeSession(NSString* window_name,
-                                              NSString* opener_id,
-                                              BOOL opened_by_dom,
-                                              int opener_navigation_index) {
+                                              BOOL opened_by_dom) {
   SetSessionController([[CRWSessionController alloc]
          initWithWindowName:window_name
-                   openerId:opener_id
                 openedByDOM:opened_by_dom
-      openerNavigationIndex:opener_navigation_index
                browserState:browser_state_]);
 }