[BattOr] Add real device smoke test

common/battor/battor/battor_wrapper.py

Index: common/battor/battor/battor_wrapper.py
diff --git a/common/battor/battor/battor_wrapper.py b/common/battor/battor/battor_wrapper.py
index e2966eb3c54e52e0232890b8d93dc03255580f7a..d2ca5c23ebb2cfbf27fd9e411d8164ad3df027cd 100644
--- a/common/battor/battor/battor_wrapper.py
+++ b/common/battor/battor/battor_wrapper.py
@@ -14,6 +14,15 @@ import dependency_manager
 from devil.utils import battor_device_mapping
 from devil.utils import find_usb_devices
 
+sys.path.append(

[nednguyen, 2016/04/26 03:47:14]

sys.path.insert(1, ...)

It's using some serial lib in
/usr/lib/python2.7/dist-packages/serial/__init__.pyc. Guido probably regrets how
he designed the sys.path 

+    os.path.join(os.path.dirname(__file__), '..', '..', '..', 'telemetry',
+                 'third_party', 'pyserial'))
+try:
+  import serial
+  from serial.tools import list_ports
+except:
+  print serial.__file__
+  raise
 
 class BattorWrapper(object):
   """A class for communicating with a BattOr in python."""
@@ -128,9 +137,11 @@ class BattorWrapper(object):
       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:
+          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):