Remove the concept of currentItemIndex

ios/web/public/test/fakes/test_navigation_manager.mm

Index: ios/web/public/test/fakes/test_navigation_manager.mm
diff --git a/ios/web/public/test/fakes/test_navigation_manager.mm b/ios/web/public/test/fakes/test_navigation_manager.mm
index 49cbc3b984ae419b0a460b60a6ee83a146ae17d1..1c95c4e52e637b94b397e699ab1e3e573ec58096 100644
--- a/ios/web/public/test/fakes/test_navigation_manager.mm
+++ b/ios/web/public/test/fakes/test_navigation_manager.mm
@@ -79,18 +79,13 @@
   return items_[index].get();
 }
 
-int TestNavigationManager::GetCurrentItemIndex() const {
-  return items_index_;
-}
-
-void TestNavigationManager::SetCurrentItemIndex(const int index) {
+void TestNavigationManager::SetLastCommittedItemIndex(const int index) {
   DCHECK(index == -1 || index >= 0 && index < GetItemCount());
   items_index_ = index;
 }
 
 int TestNavigationManager::GetLastCommittedItemIndex() const {
-  NOTREACHED();
-  return 0;
+  return items_index_;
 }
 
 int TestNavigationManager::GetPendingItemIndex() const {
@@ -171,7 +166,7 @@
   items_.push_back(web::NavigationItem::Create());
   items_.back()->SetTransitionType(transition);
   items_.back()->SetURL(url);
-  SetCurrentItemIndex(GetItemCount() - 1);
+  SetLastCommittedItemIndex(GetItemCount() - 1);
 }
 
 }  // namespace web