Fix typing error in forwarder.py.

build/android/pylib/forwarder.py

 # Copyright (c) 2012 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 fcntl
 import logging
 import os
 import psutil
 import re
 import sys
@@ skipping 121 matching lines @@
     """Unmaps all the previously forwarded ports for the provided device.
 
     Args:
       adb: An AndroidCommands instance.
       port_pairs: A list of tuples (device_port, host_port) to unmap.
     """
     with _FileLock(Forwarder._LOCK_PATH):
       port_map = Forwarder._GetInstanceLocked(
           None, None)._device_to_host_port_map
       adb_serial = adb.Adb().GetSerialNumber()
-      for ((device_serial, device_port), _) in port_map:
+      for (device_serial, device_port) in port_map.keys():
         if adb_serial == device_serial:
           Forwarder._UnmapDevicePortLocked(device_port, adb)
 
   @staticmethod
   def DevicePortForHostPort(host_port):
     """Returns the device port that corresponds to a given host port."""
     with _FileLock(Forwarder._LOCK_PATH):
       (device_serial, device_port) = Forwarder._GetInstanceLocked(
           None, None)._host_to_device_port_map.get(host_port)
       return device_port
@@ skipping 160 matching lines @@
                                  Forwarder._DEVICE_FORWARDER_PATH))
     # TODO(pliard): Remove the following call to KillAllBlocking() when we are
     # sure that the old version of device_forwarder (not supporting
     # 'kill-server') is not running on the bots anymore.
     timeout_sec = 5
     processes_killed = adb.KillAllBlocking('device_forwarder', timeout_sec)
     if not processes_killed:
       pids = adb.ExtractPid('device_forwarder')
       if pids:
         raise Exception('Timed out while killing device_forwarder')