Add WebStateListOrderController to control WebState insertion.

ios/chrome/browser/tabs/tab_model_order_controller.h

 // Copyright 2012 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_CHROME_BROWSER_TABS_TAB_MODEL_ORDER_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_TABS_TAB_MODEL_ORDER_CONTROLLER_H_
 
 #import <Foundation/Foundation.h>
 
 #import "ios/chrome/browser/tabs/tab_model.h"
-#include "ui/base/page_transition_types.h"
-
-namespace TabModelOrderConstants {
-
-// InsertionAdjacency allows different links to choose to open tabs directly
-// before or after a given tab, depending on context.
-enum InsertionAdjacency {
-  // Insert a card just before (to the left of) a given card.
-  kAdjacentBefore,
-  // Insert a card just after (to the right of) a given card.
-  kAdjacentAfter,
-};
-
-}  // namespace TabModelOrderConstants
 
 // An object that allows different types of ordering and reselection to be
 // heuristics plugged into a TabStripModel. Closely parallels
 // chrome/browser/tabs/tab_strip_model_order_controller.h
 // but without the dependence on TabContentsWrapper and TabStripModel.
 @interface TabModelOrderController : NSObject
 
 // Initializer, |model| must be non-nil and is not retained.
 - (instancetype)initWithTabModel:(TabModel*)model;
 
-// Determines where to place a newly opened tab by using the transition and
-// adjacency flags.
-- (NSUInteger)insertionIndexForTab:(Tab*)newTab
-                        transition:(ui::PageTransition)transition
-                            opener:(Tab*)parentTab
-                         adjacency:(TabModelOrderConstants::InsertionAdjacency)
-                                       adjacency;
-
-// Returns the index at which to append tabs.
-- (NSUInteger)insertionIndexForAppending;
-
 // Returns the tab in which to shift selection after a tab is closed. May
 // return nil if there are no more tabs.
 - (Tab*)determineNewSelectedTabFromRemovedTab:(Tab*)removedTab;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_TABS_TAB_MODEL_ORDER_CONTROLLER_H_