[Android] Add LogcatMonitor.

build/android/pylib/device/device_utils.py

 # Copyright 2014 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.
 
 """Provides a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
-# pylint: disable=W0613
+# pylint: disable=unused-argument
 
 import logging
 import multiprocessing
 import os
 import re
 import sys
 import tempfile
 import time
 import zipfile
 
 import pylib.android_commands
 from pylib import cmd_helper
 from pylib import constants
 from pylib.device import adb_wrapper
 from pylib.device import decorators
 from pylib.device import device_errors
 from pylib.device import intent
+from pylib.device import logcat_monitor
 from pylib.device.commands import install_commands
 from pylib.utils import apk_helper
 from pylib.utils import device_temp_file
 from pylib.utils import host_utils
 from pylib.utils import md5sum
 from pylib.utils import parallelizer
 from pylib.utils import timeout_retry
 from pylib.utils import zip_utils
 
 _DEFAULT_TIMEOUT = 30
@@ skipping 1244 matching lines @@
     Returns:
       A 2-tuple containing:
         - A dict containing the overall memory usage statistics for the PID.
         - A dict containing memory usage statistics broken down by mapping.
 
     Raises:
       CommandTimeoutError on timeout.
     """
     return self.old_interface.GetMemoryUsageForPid(pid)
 
+  @decorators.WithTimeoutAndRetriesFromInstance()
+  def GetLogcatMonitor(self, timeout=None, retries=None, *args, **kwargs):
+    """Returns a new LogcatMonitor associated with this device."""
+    return logcat_monitor.LogcatMonitor(self.adb, *args, **kwargs)
+
   def __str__(self):
     """Returns the device serial."""
     return self.adb.GetDeviceSerial()
 
   @classmethod
   def parallel(cls, devices=None, async=False):
     """Creates a Parallelizer to operate over the provided list of devices.
 
     If |devices| is either |None| or an empty list, the Parallelizer will
     operate over all attached devices.
 
     Args:
       devices: A list of either DeviceUtils instances or objects from
                from which DeviceUtils instances can be constructed. If None,
                all attached devices will be used.
       async: If true, returns a Parallelizer that runs operations
              asynchronously.
 
     Returns:
       A Parallelizer operating over |devices|.
     """
     if not devices:
       devices = adb_wrapper.AdbWrapper.GetDevices()
     devices = [d if isinstance(d, cls) else cls(d) for d in devices]
     if async:
       return parallelizer.Parallelizer(devices)
     else:
       return parallelizer.SyncParallelizer(devices)