Remove DOMAutomationController::automation_id_

content/renderer/dom_automation_controller.h

 // Copyright (c) 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 CONTENT_RENDERER_DOM_AUTOMATION_CONTROLLER_H_
 #define CONTENT_RENDERER_DOM_AUTOMATION_CONTROLLER_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
@@ skipping 102 matching lines @@
 
   // gin::WrappableBase
   gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
       v8::Isolate* isolate) override;
 
   // RenderFrameObserver
   void OnDestruct() override;
   void DidCreateScriptContext(v8::Local<v8::Context> context,
                               int world_id) override;
 
-  int automation_id_;  // routing id to be used by the next channel.
-
   DISALLOW_COPY_AND_ASSIGN(DomAutomationController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_DOM_AUTOMATION_CONTROLLER_H_