[BattOr] Add real device smoke test

common/battor/battor/battor_wrapper.py

 # Copyright 2016 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.
 
 import os
 import platform
 import subprocess
 import sys
 import tempfile
 import time
 
 from battor import battor_error
 import dependency_manager
 from devil.utils import battor_device_mapping
 from devil.utils import find_usb_devices
 
+sys.path.insert(

[charliea (OOO until 10-5), 2016/04/29 15:11:07]

I think that this should be added here:

https://cs.corp.google.com/github/catapult-project/catapult/telemetry/telemet...

That way, you can just say 'import serial'

[rnephew (Reviews Here), 2016/04/29 17:05:57]

Will that work, this being part of common? Or do you mean add it to __init__.py
in common/battor/battor?

Adding there as I assume thats what was intended. 

[charliea (OOO until 10-5), 2016/04/29 17:18:17]

Uhhh... sure, let's pretend like I was smart enough to suggest that :)

+    1, os.path.join(os.path.dirname(__file__), '..', '..', '..', 'telemetry',
+                    'third_party', 'pyserial'))
+import serial
+from serial.tools import list_ports
 
 class BattorWrapper(object):
   """A class for communicating with a BattOr in python."""
   _START_TRACING_CMD = 'StartTracing'
   _STOP_TRACING_CMD = 'StopTracing'
   _SUPPORTS_CLOCKSYNC_CMD = 'SupportsExplicitClockSync'
   _RECORD_CLOCKSYNC_CMD = 'RecordClockSyncMarker'
   _SUPPORTED_PLATFORMS = ['android', 'chromeos', 'linux', 'mac', 'win']
 
   def __init__(self, target_platform, android_device=None, battor_path=None,
@@ skipping 94 matching lines @@
       raise TypeError('sync_id must be a string.')
     self._SendBattorCommand('%s %s' % (self._RECORD_CLOCKSYNC_CMD, sync_id))
 
   def _GetBattorPath(self, target_platform, android_device=None,
                      battor_path=None, battor_map_file=None, battor_map=None):
     """Determines most likely path to the correct BattOr."""
     if target_platform not in self._SUPPORTED_PLATFORMS:
       raise battor_error.BattorError(
           '%s is an unsupported platform.' % target_platform)
     if target_platform in ['win']:
-      # TODO: We need a way to automatically detect correct port.
-      # crbug.com/60397
-      return 'COM3'
+      for (port, desc, _) in serial.tools.list_ports.comports():
+        if 'USB Serial Port' in desc:

[charliea (OOO until 10-5), 2016/04/29 15:11:07]

Can you add a comment describing why this is necessary? Something like:

Right now, the BattOr agent binary isn't able to automatically detect the BattOr
port on Windows. To get around this, we know that the BattOr shows up with a
name of 'USB Serial Port', so use the COM port that corresponds to a device with
that name.

[rnephew (Reviews Here), 2016/04/29 17:05:57]

Done.

+          return port
+      raise battor_error.BattorError(
+          'Could not find BattOr attached to machine.')
     device_tree = find_usb_devices.GetBusNumberToDeviceTreeMap(fast=True)
     if battor_path:
       if not isinstance(battor_path, basestring):
         raise battor_error.BattorError('An invalid BattOr path was specified.')
       return battor_path
 
     if target_platform == 'android':
       if not android_device:
         raise battor_error.BattorError(
             'Must specify device for Android platform.')
@@ skipping 24 matching lines @@
     status = self._SendBattorCommandImpl(cmd, return_results=check_return)
     if check_return and not 'Done.' in status:
       raise battor_error.BattorError(
           'BattOr did not complete command \'%s\' correctly.\n'
           'Outputted: %s' % (cmd, status))
     return status
 
   def _StartShellImpl(self, battor_cmd):
     return subprocess.Popen(
         battor_cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, shell=False)