[battor agent] Move code for stringifying bytes into a util file

tools/battor_agent/battor_agent.gyp

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'battor_agent',
       'type': 'executable',
       'include_dirs': [
@@ skipping 21 matching lines @@
         'battor_connection.cc',
         'battor_connection.h',
         'battor_connection_impl.cc',
         'battor_connection_impl.h',
         'battor_error.cc',
         'battor_error.h',
         'battor_finder.cc',
         'battor_finder.h',
         'battor_sample_converter.cc',
         'battor_sample_converter.h',
+        'serial_utils.cc',
+        'serial_utils.h',
       ],
       'dependencies': [
         '../../base/base.gyp:base',
         '../../device/serial/serial.gyp:device_serial',
         '../../device/serial/serial.gyp:device_serial_mojo',
       ]
     },
     {
       'target_name': 'battor_agent_unittests',
       'type': '<(gtest_target_type)',
       'dependencies': [
         'battor_agent_lib',
         '../../base/base.gyp:base',
         '../../base/base.gyp:run_all_unittests',
         '../../base/base.gyp:test_support_base',
         '../../device/serial/serial.gyp:device_serial',
         '../../device/serial/serial.gyp:device_serial_test_util',
         '../../mojo/mojo_edk.gyp:mojo_system_impl',
         '../../testing/gmock.gyp:gmock',
         '../../testing/gtest.gyp:gtest',
       ],
       'sources': [
         'battor_agent_unittest.cc',
         'battor_connection_impl_unittest.cc',
         'battor_protocol_types_unittest.cc',
         'battor_sample_converter_unittest.cc',
+        'serial_utils_unittest.cc',        
       ],
     },
   ],
   'conditions': [
     ['test_isolation_mode != "noop"', {
       'targets': [
         {
           'target_name': 'battor_agent_unittests_run',
           'type': 'none',
           'dependencies': [
             'battor_agent_unittests',
           ],
           'includes': [
             '../../build/isolate.gypi',
           ],
           'sources': [
             'battor_agent_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }