[devil] Reenable USB reset in device_recovery behind a flag.

devil/devil/android/tools/device_recovery.py

Index: devil/devil/android/tools/device_recovery.py
diff --git a/devil/devil/android/tools/device_recovery.py b/devil/devil/android/tools/device_recovery.py
index 4852814a1b5840c2865fd1d2251466e6ac9f216b..a7844e262eabcacd6b8cf5599876ff319f2816db 100755
--- a/devil/devil/android/tools/device_recovery.py
+++ b/devil/devil/android/tools/device_recovery.py
@@ -102,7 +102,7 @@ def RecoverDevice(device, blacklist, should_reboot=lambda device: True):
                          reason='reboot_timeout')
 
 
-def RecoverDevices(devices, blacklist):
+def RecoverDevices(devices, blacklist, enable_usb_reset=False):
   """Attempts to recover any inoperable devices in the provided list.
 
   Args:
@@ -143,8 +143,11 @@ def RecoverDevices(devices, blacklist):
     try:
       # TODO(crbug.com/642194): Resetting may be causing more harm
       # (specifically, kernel panics) than it does good.
-      logging.warning('USB reset disabled for %s (crbug.com/642914)',
-                      serial)
+      if enable_usb_reset:
+        reset_usb.reset_android_usb(serial)
+      else:
+        logging.warning('USB reset disabled for %s (crbug.com/642914)',
+                        serial)
     except IOError:
       logging.exception('Unable to reset USB for %s.', serial)
       if blacklist:
@@ -167,6 +170,8 @@ def main():
   parser.add_argument('--known-devices-file', action='append', default=[],
                       dest='known_devices_files',
                       help='Path to known device lists.')
+  parser.add_argument('--enable-usb-reset', action='store_true',
+                      help='Reset USB if necessary.')
   parser.add_argument('-v', '--verbose', action='count', default=1,
                       help='Log more information.')
 
@@ -189,7 +194,7 @@ def main():
   devices = [device_utils.DeviceUtils(s)
              for s in expected_devices.union(usb_devices)]
 
-  RecoverDevices(devices, blacklist)
+  RecoverDevices(devices, blacklist, enable_usb_reset=args.enable_usb_reset)
 
 
 if __name__ == '__main__':