Remove the concept of currentItemIndex

ios/web/public/navigation_manager.h

 // Copyright 2013 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_PUBLIC_NAVIGATION_MANAGER_H_
 #define IOS_WEB_PUBLIC_NAVIGATION_MANAGER_H_
 
 #include <stddef.h>
 
 #import "base/mac/scoped_nsobject.h"
@@ skipping 102 matching lines @@
       BrowserURLRewriter::URLRewriter rewriter) = 0;
 
   // Returns the number of items in the NavigationManager, excluding
   // pending and transient entries.
   // TODO(crbug.com/533848): Update to return size_t.
   virtual int GetItemCount() const = 0;
 
   // Returns the committed NavigationItem at |index|.
   virtual NavigationItem* GetItemAtIndex(size_t index) const = 0;
 
-  // Returns the index from which web would go back/forward or reload.
-  // TODO(crbug.com/533848): Update to return size_t.
-  virtual int GetCurrentItemIndex() const = 0;
-
   // Returns the index of the last committed item or -1 if the last
   // committed item correspond to a new navigation.
   // TODO(crbug.com/533848): Update to return size_t.
   virtual int GetLastCommittedItemIndex() const = 0;
 
   // Returns the index of the pending item or -1 if the pending item
   // corresponds to a new navigation.
   // TODO(crbug.com/533848): Update to return size_t.
   virtual int GetPendingItemIndex() const = 0;
 
@@ skipping 52 matching lines @@
   // Forces the pending item to be loaded using desktop user agent. Note that
   // the pending item may or may not already exist.
   // TODO(crbug.com/692303): Remove this when overriding the user agent doesn't
   // create a new NavigationItem.
   virtual void OverrideDesktopUserAgentForNextPendingItem() = 0;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_PUBLIC_NAVIGATION_MANAGER_H_