Makes the BattOrAgent asynchronous

tools/battor_agent/BUILD.gn

 # 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.
 
 executable("battor_agent") {
   sources = [
     "battor_agent_bin.cc",
   ]
   deps = [
     ":battor_agent_lib",
+    "//base",
   ]
 }
 
 static_library("battor_agent_lib") {
   sources = [
     "battor_agent.cc",
     "battor_agent.h",
   ]
   deps = [
     "//base",
   ]
 }