Remove obsolete code in TabModelOrderController.

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 {
 
-// InsertionPolicy is a general policy for opening all new tabs.
-enum InsertionPolicy {
-  // Newly created tabs are created after the selection. This is the default.
-  kInsertAfter,
-  // Newly created tabs are inserted before the selection.
-  kInsertBefore,
-};
-
 // 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 {
- @private
-  TabModel* model_;  // weak, owns us
-  TabModelOrderConstants::InsertionPolicy insertionPolicy_;
-}
-
-// Sets the insertion policy for new tabs. Default is |kInsertAfter|.
-@property(nonatomic, assign)
-    TabModelOrderConstants::InsertionPolicy insertionPolicy;
+@interface TabModelOrderController : NSObject
 
 // Initializer, |model| must be non-nil and is not retained.
-- (id)initWithTabModel:(TabModel*)model;
+- (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, based on |insertionPolicy|.
+// 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_