[iOS Clean] Wired up ContextMenuCommands.

ios/clean/chrome/browser/ui/context_menu/context_menu_mediator.h

 // Copyright 2017 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_CLEAN_CHROME_BROWSER_UI_CONTEXT_MENU_CONTEXT_MENU_MEDIATOR_H_
 #define IOS_CLEAN_CHROME_BROWSER_UI_CONTEXT_MENU_CONTEXT_MENU_MEDIATOR_H_
 
 #import <Foundation/Foundation.h>
 
 @protocol ContextMenuConsumer;
+@class ContextMenuContextImpl;
 
 // A mediator object that provides configuration information for a context
 // menu.
 @interface ContextMenuMediator : NSObject
 
-// Creates a new mediator with the non-nil consumer |consumer|.
-- (instancetype)initWithConsumer:(id<ContextMenuConsumer>)consumer;
+// Populates |consumer| with alert items for actions appropriate for |context|.
++ (void)updateConsumer:(id<ContextMenuConsumer>)consumer
+           withContext:(ContextMenuContextImpl*)context;
+
+// A ContextMenuConsumer only requires configuration only once, then is
+// immutable.  As a result, there is no need to instantiate an object to manage
+// ongoing consumer updates; use |+updateConsumer:withContext:| instead.
+- (instancetype)init NS_UNAVAILABLE;
 
 @end
 
 #endif  // IOS_CLEAN_CHROME_BROWSER_UI_CONTEXT_MENU_CONTEXT_MENU_MEDIATOR_H_