remove dead code from devtools worker management

content/browser/devtools/worker_devtools_manager.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_BROWSER_DEVTOOLS_WORKER_DEVTOOLS_MANAGER_H_
 #define CONTENT_BROWSER_DEVTOOLS_WORKER_DEVTOOLS_MANAGER_H_
 
 #include <list>
 #include <map>
 #include <string>
@@ skipping 14 matching lines @@
   class WorkerDevToolsAgentHost;
 
   // Returns the WorkerDevToolsManager singleton.
   static WorkerDevToolsManager* GetInstance();
 
   // Called on the UI thread.
   static DevToolsAgentHost* GetDevToolsAgentHostForWorker(
       int worker_process_id,
       int worker_route_id);
 
-  // Called on the UI thread.
-  static bool HasDevToolsAgentHostForWorker(
-      int worker_process_id,
-      int worker_route_id);
-
   void ForwardToDevToolsClient(int worker_process_id,
                                int worker_route_id,
                                const std::string& message);
   void SaveAgentRuntimeState(int worker_process_id,
                              int worker_route_id,
                              const std::string& state);
 
   // Called on the IO thread.
   void WorkerCreated(
       WorkerProcessHost* process,
@@ skipping 55 matching lines @@
   // worker.
   // - Existing DevTools client was reattached to the new worker.
   PausedWorkers paused_workers_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerDevToolsManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_WORKER_DEVTOOLS_MANAGER_H_