Removing file_thread_task_runner parameter from SerialIoHandler

tools/battor_agent/battor_agent.h

 // Copyright 2015 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 TOOLS_BATTOR_AGENT_BATTOR_AGENT_H_
 #define TOOLS_BATTOR_AGENT_BATTOR_AGENT_H_
 
 #include <map>
 
 #include "base/cancelable_callback.h"
@@ skipping 33 matching lines @@
     virtual void OnStopTracingComplete(const std::string& trace,
                                        BattOrError error) = 0;
     virtual void OnRecordClockSyncMarkerComplete(BattOrError error) = 0;
     virtual void OnGetFirmwareGitHashComplete(const std::string& version,
                                               BattOrError error) = 0;
   };
 
   BattOrAgent(
       const std::string& path,
       Listener* listener,
-      scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner);
   virtual ~BattOrAgent();
 
   void StartTracing();
   void StopTracing();
   void RecordClockSyncMarker(const std::string& marker);
   void GetFirmwareGitHash();
 
   // Returns whether the BattOr is able to record clock sync markers in its own
   // trace log.
@@ skipping 128 matching lines @@
 
   // The git hash of the BattOr firmware.
   std::string firmware_git_hash_;
 
   DISALLOW_COPY_AND_ASSIGN(BattOrAgent);
 };
 
 }  // namespace battor
 
 #endif  // TOOLS_BATTOR_AGENT_BATTOR_AGENT_H_