diff -r 000000000000 -r 6474c204b198 media/webrtc/trunk/build/android/pylib/android_commands.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/media/webrtc/trunk/build/android/pylib/android_commands.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,1071 @@
+# 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.
+
+"""Provides an interface to communicate with the device via the adb command.
+
+Assumes adb binary is currently on system path.
+"""
+
+import collections
+import datetime
+import logging
+import os
+import re
+import shlex
+import subprocess
+import sys
+import tempfile
+import time
+
+import io_stats_parser
+from pylib import pexpect
+
+CHROME_SRC = os.path.join(
+    os.path.abspath(os.path.dirname(__file__)), '..', '..', '..')
+
+sys.path.append(os.path.join(CHROME_SRC, 'third_party', 'android_testrunner'))
+import adb_interface
+
+import cmd_helper
+import errors  #  is under ../../../third_party/android_testrunner/errors.py
+
+
+# Pattern to search for the next whole line of pexpect output and capture it
+# into a match group. We can't use ^ and $ for line start end with pexpect,
+# see http://www.noah.org/python/pexpect/#doc for explanation why.
+PEXPECT_LINE_RE = re.compile('\n([^\r]*)\r')
+
+# Set the adb shell prompt to be a unique marker that will [hopefully] not
+# appear at the start of any line of a command's output.
+SHELL_PROMPT = '~+~PQ\x17RS~+~'
+
+# Java properties file
+LOCAL_PROPERTIES_PATH = '/data/local.prop'
+
+# Property in /data/local.prop that controls Java assertions.
+JAVA_ASSERT_PROPERTY = 'dalvik.vm.enableassertions'
+
+MEMORY_INFO_RE = re.compile('^(?P<key>\w+):\s+(?P<usage_kb>\d+) kB$')
+NVIDIA_MEMORY_INFO_RE = re.compile('^\s*(?P<user>\S+)\s*(?P<name>\S+)\s*'
+                                   '(?P<pid>\d+)\s*(?P<usage_bytes>\d+)$')
+
+# Keycode "enum" suitable for passing to AndroidCommands.SendKey().
+KEYCODE_HOME = 3
+KEYCODE_BACK = 4
+KEYCODE_DPAD_UP = 19
+KEYCODE_DPAD_DOWN = 20
+KEYCODE_DPAD_RIGHT = 22
+KEYCODE_ENTER = 66
+KEYCODE_MENU = 82
+
+MD5SUM_DEVICE_PATH = '/data/local/tmp/md5sum_bin'
+
+def GetEmulators():
+  """Returns a list of emulators.  Does not filter by status (e.g. offline).
+
+  Both devices starting with 'emulator' will be returned in below output:
+
+    * daemon not running. starting it now on port 5037 *
+    * daemon started successfully *
+    List of devices attached
+    027c10494100b4d7        device
+    emulator-5554   offline
+    emulator-5558   device
+  """
+  re_device = re.compile('^emulator-[0-9]+', re.MULTILINE)
+  devices = re_device.findall(cmd_helper.GetCmdOutput(['adb', 'devices']))
+  return devices
+
+
+def GetAVDs():
+  """Returns a list of AVDs."""
+  re_avd = re.compile('^[ ]+Name: ([a-zA-Z0-9_:.-]+)', re.MULTILINE)
+  avds = re_avd.findall(cmd_helper.GetCmdOutput(['android', 'list', 'avd']))
+  return avds
+
+
+def GetAttachedDevices():
+  """Returns a list of attached, online android devices.
+
+  If a preferred device has been set with ANDROID_SERIAL, it will be first in
+  the returned list.
+
+  Example output:
+
+    * daemon not running. starting it now on port 5037 *
+    * daemon started successfully *
+    List of devices attached
+    027c10494100b4d7        device
+    emulator-5554   offline
+  """
+  re_device = re.compile('^([a-zA-Z0-9_:.-]+)\tdevice$', re.MULTILINE)
+  devices = re_device.findall(cmd_helper.GetCmdOutput(['adb', 'devices']))
+  preferred_device = os.environ.get('ANDROID_SERIAL')
+  if preferred_device in devices:
+    devices.remove(preferred_device)
+    devices.insert(0, preferred_device)
+  return devices
+
+def _GetFilesFromRecursiveLsOutput(path, ls_output, re_file, utc_offset=None):
+  """Gets a list of files from `ls` command output.
+
+  Python's os.walk isn't used because it doesn't work over adb shell.
+
+  Args:
+    path: The path to list.
+    ls_output: A list of lines returned by an `ls -lR` command.
+    re_file: A compiled regular expression which parses a line into named groups
+        consisting of at minimum "filename", "date", "time", "size" and
+        optionally "timezone".
+    utc_offset: A 5-character string of the form +HHMM or -HHMM, where HH is a
+        2-digit string giving the number of UTC offset hours, and MM is a
+        2-digit string giving the number of UTC offset minutes. If the input
+        utc_offset is None, will try to look for the value of "timezone" if it
+        is specified in re_file.
+
+  Returns:
+    A dict of {"name": (size, lastmod), ...} where:
+      name: The file name relative to |path|'s directory.
+      size: The file size in bytes (0 for directories).
+      lastmod: The file last modification date in UTC.
+  """
+  re_directory = re.compile('^%s/(?P<dir>[^:]+):$' % re.escape(path))
+  path_dir = os.path.dirname(path)
+
+  current_dir = ''
+  files = {}
+  for line in ls_output:
+    directory_match = re_directory.match(line)
+    if directory_match:
+      current_dir = directory_match.group('dir')
+      continue
+    file_match = re_file.match(line)
+    if file_match:
+      filename = os.path.join(current_dir, file_match.group('filename'))
+      if filename.startswith(path_dir):
+        filename = filename[len(path_dir)+1:]
+      lastmod = datetime.datetime.strptime(
+          file_match.group('date') + ' ' + file_match.group('time')[:5],
+          '%Y-%m-%d %H:%M')
+      if not utc_offset and 'timezone' in re_file.groupindex:
+        utc_offset = file_match.group('timezone')
+      if isinstance(utc_offset, str) and len(utc_offset) == 5:
+        utc_delta = datetime.timedelta(hours=int(utc_offset[1:3]),
+                                       minutes=int(utc_offset[3:5]))
+        if utc_offset[0:1] == '-':
+          utc_delta = -utc_delta
+        lastmod -= utc_delta
+      files[filename] = (int(file_match.group('size')), lastmod)
+  return files
+
+def _ComputeFileListHash(md5sum_output):
+  """Returns a list of MD5 strings from the provided md5sum output."""
+  return [line.split('  ')[0] for line in md5sum_output]
+
+def _HasAdbPushSucceeded(command_output):
+  """Returns whether adb push has succeeded from the provided output."""
+  if not command_output:
+    return False
+  # Success looks like this: "3035 KB/s (12512056 bytes in 4.025s)"
+  # Errors look like this: "failed to copy  ... "
+  if not re.search('^[0-9]', command_output.splitlines()[-1]):
+    logging.critical('PUSH FAILED: ' + command_output)
+    return False
+  return True
+
+def GetLogTimestamp(log_line, year):
+  """Returns the timestamp of the given |log_line| in the given year."""
+  try:
+    return datetime.datetime.strptime('%s-%s' % (year, log_line[:18]),
+                                      '%Y-%m-%d %H:%M:%S.%f')
+  except (ValueError, IndexError):
+    logging.critical('Error reading timestamp from ' + log_line)
+    return None
+
+
+class AndroidCommands(object):
+  """Helper class for communicating with Android device via adb.
+
+  Args:
+    device: If given, adb commands are only send to the device of this ID.
+        Otherwise commands are sent to all attached devices.
+  """
+
+  def __init__(self, device=None):
+    self._adb = adb_interface.AdbInterface()
+    if device:
+      self._adb.SetTargetSerial(device)
+    self._logcat = None
+    self.logcat_process = None
+    self._pushed_files = []
+    self._device_utc_offset = self.RunShellCommand('date +%z')[0]
+    self._md5sum_path = ''
+    self._external_storage = ''
+
+  def Adb(self):
+    """Returns our AdbInterface to avoid us wrapping all its methods."""
+    return self._adb
+
+  def IsRootEnabled(self):
+    """Checks if root is enabled on the device."""
+    root_test_output = self.RunShellCommand('ls /root') or ['']
+    return not 'Permission denied' in root_test_output[0]
+
+  def EnableAdbRoot(self):
+    """Enables adb root on the device.
+
+    Returns:
+      True: if output from executing adb root was as expected.
+      False: otherwise.
+    """
+    return_value = self._adb.EnableAdbRoot()
+    # EnableAdbRoot inserts a call for wait-for-device only when adb logcat
+    # output matches what is expected. Just to be safe add a call to
+    # wait-for-device.
+    self._adb.SendCommand('wait-for-device')
+    return return_value
+
+  def GetDeviceYear(self):
+    """Returns the year information of the date on device."""
+    return self.RunShellCommand('date +%Y')[0]
+
+  def GetExternalStorage(self):
+    if not self._external_storage:
+      self._external_storage = self.RunShellCommand('echo $EXTERNAL_STORAGE')[0]
+      assert self._external_storage, 'Unable to find $EXTERNAL_STORAGE'
+    return self._external_storage
+
+  def WaitForDevicePm(self):
+    """Blocks until the device's package manager is available.
+
+    To workaround http://b/5201039, we restart the shell and retry if the
+    package manager isn't back after 120 seconds.
+
+    Raises:
+      errors.WaitForResponseTimedOutError after max retries reached.
+    """
+    last_err = None
+    retries = 3
+    while retries:
+      try:
+        self._adb.WaitForDevicePm()
+        return  # Success
+      except errors.WaitForResponseTimedOutError as e:
+        last_err = e
+        logging.warning('Restarting and retrying after timeout: %s', e)
+        retries -= 1
+        self.RestartShell()
+    raise last_err  # Only reached after max retries, re-raise the last error.
+
+  def RestartShell(self):
+    """Restarts the shell on the device. Does not block for it to return."""
+    self.RunShellCommand('stop')
+    self.RunShellCommand('start')
+
+  def Reboot(self, full_reboot=True):
+    """Reboots the device and waits for the package manager to return.
+
+    Args:
+      full_reboot: Whether to fully reboot the device or just restart the shell.
+    """
+    # TODO(torne): hive can't reboot the device either way without breaking the
+    # connection; work out if we can handle this better
+    if os.environ.get('USING_HIVE'):
+      logging.warning('Ignoring reboot request as we are on hive')
+      return
+    if full_reboot or not self.IsRootEnabled():
+      self._adb.SendCommand('reboot')
+      timeout = 300
+    else:
+      self.RestartShell()
+      timeout = 120
+    # To run tests we need at least the package manager and the sd card (or
+    # other external storage) to be ready.
+    self.WaitForDevicePm()
+    self.WaitForSdCardReady(timeout)
+
+  def Uninstall(self, package):
+    """Uninstalls the specified package from the device.
+
+    Args:
+      package: Name of the package to remove.
+
+    Returns:
+      A status string returned by adb uninstall
+    """
+    uninstall_command = 'uninstall %s' % package
+
+    logging.info('>>> $' + uninstall_command)
+    return self._adb.SendCommand(uninstall_command, timeout_time=60)
+
+  def Install(self, package_file_path, reinstall=False):
+    """Installs the specified package to the device.
+
+    Args:
+      package_file_path: Path to .apk file to install.
+      reinstall: Reinstall an existing apk, keeping the data.
+
+    Returns:
+      A status string returned by adb install
+    """
+    assert os.path.isfile(package_file_path), ('<%s> is not file' %
+                                               package_file_path)
+
+    install_cmd = ['install']
+
+    if reinstall:
+      install_cmd.append('-r')
+
+    install_cmd.append(package_file_path)
+    install_cmd = ' '.join(install_cmd)
+
+    logging.info('>>> $' + install_cmd)
+    return self._adb.SendCommand(install_cmd, timeout_time=2*60, retry_count=0)
+
+  def ManagedInstall(self, apk_path, keep_data=False, package_name=None,
+                     reboots_on_failure=2):
+    """Installs specified package and reboots device on timeouts.
+
+    Args:
+      apk_path: Path to .apk file to install.
+      keep_data: Reinstalls instead of uninstalling first, preserving the
+        application data.
+      package_name: Package name (only needed if keep_data=False).
+      reboots_on_failure: number of time to reboot if package manager is frozen.
+
+    Returns:
+      A status string returned by adb install
+    """
+    reboots_left = reboots_on_failure
+    while True:
+      try:
+        if not keep_data:
+          assert package_name
+          self.Uninstall(package_name)
+        install_status = self.Install(apk_path, reinstall=keep_data)
+        if 'Success' in install_status:
+          return install_status
+      except errors.WaitForResponseTimedOutError:
+        print '@@@STEP_WARNINGS@@@'
+        logging.info('Timeout on installing %s' % apk_path)
+
+      if reboots_left <= 0:
+        raise Exception('Install failure')
+
+      # Force a hard reboot on last attempt
+      self.Reboot(full_reboot=(reboots_left == 1))
+      reboots_left -= 1
+
+  def MakeSystemFolderWritable(self):
+    """Remounts the /system folder rw."""
+    out = self._adb.SendCommand('remount')
+    if out.strip() != 'remount succeeded':
+      raise errors.MsgException('Remount failed: %s' % out)
+
+  def RestartAdbServer(self):
+    """Restart the adb server."""
+    self.KillAdbServer()
+    self.StartAdbServer()
+
+  def KillAdbServer(self):
+    """Kill adb server."""
+    adb_cmd = ['adb', 'kill-server']
+    return cmd_helper.RunCmd(adb_cmd)
+
+  def StartAdbServer(self):
+    """Start adb server."""
+    adb_cmd = ['adb', 'start-server']
+    return cmd_helper.RunCmd(adb_cmd)
+
+  def WaitForSystemBootCompleted(self, wait_time):
+    """Waits for targeted system's boot_completed flag to be set.
+
+    Args:
+      wait_time: time in seconds to wait
+
+    Raises:
+      WaitForResponseTimedOutError if wait_time elapses and flag still not
+      set.
+    """
+    logging.info('Waiting for system boot completed...')
+    self._adb.SendCommand('wait-for-device')
+    # Now the device is there, but system not boot completed.
+    # Query the sys.boot_completed flag with a basic command
+    boot_completed = False
+    attempts = 0
+    wait_period = 5
+    while not boot_completed and (attempts * wait_period) < wait_time:
+      output = self._adb.SendShellCommand('getprop sys.boot_completed',
+                                          retry_count=1)
+      output = output.strip()
+      if output == '1':
+        boot_completed = True
+      else:
+        # If 'error: xxx' returned when querying the flag, it means
+        # adb server lost the connection to the emulator, so restart the adb
+        # server.
+        if 'error:' in output:
+          self.RestartAdbServer()
+        time.sleep(wait_period)
+        attempts += 1
+    if not boot_completed:
+      raise errors.WaitForResponseTimedOutError(
+          'sys.boot_completed flag was not set after %s seconds' % wait_time)
+
+  def WaitForSdCardReady(self, timeout_time):
+    """Wait for the SD card ready before pushing data into it."""
+    logging.info('Waiting for SD card ready...')
+    sdcard_ready = False
+    attempts = 0
+    wait_period = 5
+    external_storage = self.GetExternalStorage()
+    while not sdcard_ready and attempts * wait_period < timeout_time:
+      output = self.RunShellCommand('ls ' + external_storage)
+      if output:
+        sdcard_ready = True
+      else:
+        time.sleep(wait_period)
+        attempts += 1
+    if not sdcard_ready:
+      raise errors.WaitForResponseTimedOutError(
+          'SD card not ready after %s seconds' % timeout_time)
+
+  # It is tempting to turn this function into a generator, however this is not
+  # possible without using a private (local) adb_shell instance (to ensure no
+  # other command interleaves usage of it), which would defeat the main aim of
+  # being able to reuse the adb shell instance across commands.
+  def RunShellCommand(self, command, timeout_time=20, log_result=False):
+    """Send a command to the adb shell and return the result.
+
+    Args:
+      command: String containing the shell command to send. Must not include
+               the single quotes as we use them to escape the whole command.
+      timeout_time: Number of seconds to wait for command to respond before
+        retrying, used by AdbInterface.SendShellCommand.
+      log_result: Boolean to indicate whether we should log the result of the
+                  shell command.
+
+    Returns:
+      list containing the lines of output received from running the command
+    """
+    logging.info('>>> $' + command)
+    if "'" in command: logging.warning(command + " contains ' quotes")
+    result = self._adb.SendShellCommand(
+        "'%s'" % command, timeout_time).splitlines()
+    if ['error: device not found'] == result:
+      raise errors.DeviceUnresponsiveError('device not found')
+    if log_result:
+      logging.info('\n>>> '.join(result))
+    return result
+
+  def KillAll(self, process):
+    """Android version of killall, connected via adb.
+
+    Args:
+      process: name of the process to kill off
+
+    Returns:
+      the number of processes killed
+    """
+    pids = self.ExtractPid(process)
+    if pids:
+      self.RunShellCommand('kill ' + ' '.join(pids))
+    return len(pids)
+
+  def KillAllBlocking(self, process, timeout_sec):
+    """Blocking version of killall, connected via adb.
+
+    This waits until no process matching the corresponding name appears in ps'
+    output anymore.
+
+    Args:
+      process: name of the process to kill off
+      timeout_sec: the timeout in seconds
+
+    Returns:
+      the number of processes killed
+    """
+    processes_killed = self.KillAll(process)
+    if processes_killed:
+      elapsed = 0
+      wait_period = 0.1
+      # Note that this doesn't take into account the time spent in ExtractPid().
+      while self.ExtractPid(process) and elapsed < timeout_sec:
+        time.sleep(wait_period)
+        elapsed += wait_period
+      if elapsed >= timeout_sec:
+        return 0
+    return processes_killed
+
+  def StartActivity(self, package, activity, wait_for_completion=False,
+                    action='android.intent.action.VIEW',
+                    category=None, data=None,
+                    extras=None, trace_file_name=None):
+    """Starts |package|'s activity on the device.
+
+    Args:
+      package: Name of package to start (e.g. 'com.google.android.apps.chrome').
+      activity: Name of activity (e.g. '.Main' or
+        'com.google.android.apps.chrome.Main').
+      wait_for_completion: wait for the activity to finish launching (-W flag).
+      action: string (e.g. "android.intent.action.MAIN"). Default is VIEW.
+      category: string (e.g. "android.intent.category.HOME")
+      data: Data string to pass to activity (e.g. 'http://www.example.com/').
+      extras: Dict of extras to pass to activity. Values are significant.
+      trace_file_name: If used, turns on and saves the trace to this file name.
+    """
+    cmd = 'am start -a %s' % action
+    if wait_for_completion:
+      cmd += ' -W'
+    if category:
+      cmd += ' -c %s' % category
+    if package and activity:
+      cmd += ' -n %s/%s' % (package, activity)
+    if data:
+      cmd += ' -d "%s"' % data
+    if extras:
+      for key in extras:
+        value = extras[key]
+        if isinstance(value, str):
+          cmd += ' --es'
+        elif isinstance(value, bool):
+          cmd += ' --ez'
+        elif isinstance(value, int):
+          cmd += ' --ei'
+        else:
+          raise NotImplementedError(
+              'Need to teach StartActivity how to pass %s extras' % type(value))
+        cmd += ' %s %s' % (key, value)
+    if trace_file_name:
+      cmd += ' --start-profiler ' + trace_file_name
+    self.RunShellCommand(cmd)
+
+  def GoHome(self):
+    """Tell the device to return to the home screen. Blocks until completion."""
+    self.RunShellCommand('am start -W '
+        '-a android.intent.action.MAIN -c android.intent.category.HOME')
+
+  def CloseApplication(self, package):
+    """Attempt to close down the application, using increasing violence.
+
+    Args:
+      package: Name of the process to kill off, e.g.
+      com.google.android.apps.chrome
+    """
+    self.RunShellCommand('am force-stop ' + package)
+
+  def ClearApplicationState(self, package):
+    """Closes and clears all state for the given |package|."""
+    self.CloseApplication(package)
+    self.RunShellCommand('rm -r /data/data/%s/app_*' % package)
+    self.RunShellCommand('rm -r /data/data/%s/cache/*' % package)
+    self.RunShellCommand('rm -r /data/data/%s/files/*' % package)
+    self.RunShellCommand('rm -r /data/data/%s/shared_prefs/*' % package)
+
+  def SendKeyEvent(self, keycode):
+    """Sends keycode to the device.
+
+    Args:
+      keycode: Numeric keycode to send (see "enum" at top of file).
+    """
+    self.RunShellCommand('input keyevent %d' % keycode)
+
+  def PushIfNeeded(self, local_path, device_path):
+    """Pushes |local_path| to |device_path|.
+
+    Works for files and directories. This method skips copying any paths in
+    |test_data_paths| that already exist on the device with the same hash.
+
+    All pushed files can be removed by calling RemovePushedFiles().
+    """
+    assert os.path.exists(local_path), 'Local path not found %s' % local_path
+
+    if not self._md5sum_path:
+      default_build_type = os.environ.get('BUILD_TYPE', 'Debug')
+      md5sum_path = '%s/out/%s/md5sum_bin' % (CHROME_SRC, default_build_type)
+      if not os.path.exists(md5sum_path):
+        md5sum_path = '%s/out/Release/md5sum_bin' % (CHROME_SRC)
+        if not os.path.exists(md5sum_path):
+          print >> sys.stderr, 'Please build md5sum.'
+          sys.exit(1)
+      command = 'push %s %s' % (md5sum_path, MD5SUM_DEVICE_PATH)
+      assert _HasAdbPushSucceeded(self._adb.SendCommand(command))
+      self._md5sum_path = md5sum_path
+
+    self._pushed_files.append(device_path)
+    hashes_on_device = _ComputeFileListHash(
+        self.RunShellCommand(MD5SUM_DEVICE_PATH + ' ' + device_path))
+    assert os.path.exists(local_path), 'Local path not found %s' % local_path
+    hashes_on_host = _ComputeFileListHash(
+        subprocess.Popen(
+            '%s_host %s' % (self._md5sum_path, local_path),
+            stdout=subprocess.PIPE, shell=True).stdout)
+    if hashes_on_device == hashes_on_host:
+      return
+
+    # They don't match, so remove everything first and then create it.
+    if os.path.isdir(local_path):
+      self.RunShellCommand('rm -r %s' % device_path, timeout_time=2*60)
+      self.RunShellCommand('mkdir -p %s' % device_path)
+
+    # NOTE: We can't use adb_interface.Push() because it hardcodes a timeout of
+    # 60 seconds which isn't sufficient for a lot of users of this method.
+    push_command = 'push %s %s' % (local_path, device_path)
+    logging.info('>>> $' + push_command)
+    output = self._adb.SendCommand(push_command, timeout_time=30*60)
+    assert _HasAdbPushSucceeded(output)
+
+
+  def GetFileContents(self, filename, log_result=False):
+    """Gets contents from the file specified by |filename|."""
+    return self.RunShellCommand('if [ -f "' + filename + '" ]; then cat "' +
+                                filename + '"; fi', log_result=log_result)
+
+  def SetFileContents(self, filename, contents):
+    """Writes |contents| to the file specified by |filename|."""
+    with tempfile.NamedTemporaryFile() as f:
+      f.write(contents)
+      f.flush()
+      self._adb.Push(f.name, filename)
+
+  def RemovePushedFiles(self):
+    """Removes all files pushed with PushIfNeeded() from the device."""
+    for p in self._pushed_files:
+      self.RunShellCommand('rm -r %s' % p, timeout_time=2*60)
+
+  def ListPathContents(self, path):
+    """Lists files in all subdirectories of |path|.
+
+    Args:
+      path: The path to list.
+
+    Returns:
+      A dict of {"name": (size, lastmod), ...}.
+    """
+    # Example output:
+    # /foo/bar:
+    # -rw-r----- 1 user group   102 2011-05-12 12:29:54.131623387 +0100 baz.txt
+    re_file = re.compile('^-(?P<perms>[^\s]+)\s+'
+                         '(?P<user>[^\s]+)\s+'
+                         '(?P<group>[^\s]+)\s+'
+                         '(?P<size>[^\s]+)\s+'
+                         '(?P<date>[^\s]+)\s+'
+                         '(?P<time>[^\s]+)\s+'
+                         '(?P<filename>[^\s]+)$')
+    return _GetFilesFromRecursiveLsOutput(
+        path, self.RunShellCommand('ls -lR %s' % path), re_file,
+        self._device_utc_offset)
+
+
+  def SetJavaAssertsEnabled(self, enable):
+    """Sets or removes the device java assertions property.
+
+    Args:
+      enable: If True the property will be set.
+
+    Returns:
+      True if the file was modified (reboot is required for it to take effect).
+    """
+    # First ensure the desired property is persisted.
+    temp_props_file = tempfile.NamedTemporaryFile()
+    properties = ''
+    if self._adb.Pull(LOCAL_PROPERTIES_PATH, temp_props_file.name):
+      properties = file(temp_props_file.name).read()
+    re_search = re.compile(r'^\s*' + re.escape(JAVA_ASSERT_PROPERTY) +
+                           r'\s*=\s*all\s*$', re.MULTILINE)
+    if enable != bool(re.search(re_search, properties)):
+      re_replace = re.compile(r'^\s*' + re.escape(JAVA_ASSERT_PROPERTY) +
+                              r'\s*=\s*\w+\s*$', re.MULTILINE)
+      properties = re.sub(re_replace, '', properties)
+      if enable:
+        properties += '\n%s=all\n' % JAVA_ASSERT_PROPERTY
+
+      file(temp_props_file.name, 'w').write(properties)
+      self._adb.Push(temp_props_file.name, LOCAL_PROPERTIES_PATH)
+
+    # Next, check the current runtime value is what we need, and
+    # if not, set it and report that a reboot is required.
+    was_set = 'all' in self.RunShellCommand('getprop ' + JAVA_ASSERT_PROPERTY)
+    if was_set == enable:
+      return False
+
+    self.RunShellCommand('setprop %s "%s"' % (JAVA_ASSERT_PROPERTY,
+                                              enable and 'all' or ''))
+    return True
+
+  def GetBuildId(self):
+    """Returns the build ID of the system (e.g. JRM79C)."""
+    build_id = self.RunShellCommand('getprop ro.build.id')[0]
+    assert build_id
+    return build_id
+
+  def GetBuildType(self):
+    """Returns the build type of the system (e.g. eng)."""
+    build_type = self.RunShellCommand('getprop ro.build.type')[0]
+    assert build_type
+    return build_type
+
+  def StartMonitoringLogcat(self, clear=True, timeout=10, logfile=None,
+                            filters=None):
+    """Starts monitoring the output of logcat, for use with WaitForLogMatch.
+
+    Args:
+      clear: If True the existing logcat output will be cleared, to avoiding
+             matching historical output lurking in the log.
+      timeout: How long WaitForLogMatch will wait for the given match
+      filters: A list of logcat filters to be used.
+    """
+    if clear:
+      self.RunShellCommand('logcat -c')
+    args = []
+    if self._adb._target_arg:
+      args += shlex.split(self._adb._target_arg)
+    args += ['logcat', '-v', 'threadtime']
+    if filters:
+      args.extend(filters)
+    else:
+      args.append('*:v')
+
+    if logfile:
+      logfile = NewLineNormalizer(logfile)
+
+    # Spawn logcat and syncronize with it.
+    for _ in range(4):
+      self._logcat = pexpect.spawn('adb', args, timeout=timeout,
+                                   logfile=logfile)
+      self.RunShellCommand('log startup_sync')
+      if self._logcat.expect(['startup_sync', pexpect.EOF,
+                              pexpect.TIMEOUT]) == 0:
+        break
+      self._logcat.close(force=True)
+    else:
+      logging.critical('Error reading from logcat: ' + str(self._logcat.match))
+      sys.exit(1)
+
+  def GetMonitoredLogCat(self):
+    """Returns an "adb logcat" command as created by pexpected.spawn."""
+    if not self._logcat:
+      self.StartMonitoringLogcat(clear=False)
+    return self._logcat
+
+  def WaitForLogMatch(self, success_re, error_re, clear=False):
+    """Blocks until a matching line is logged or a timeout occurs.
+
+    Args:
+      success_re: A compiled re to search each line for.
+      error_re: A compiled re which, if found, terminates the search for
+          |success_re|. If None is given, no error condition will be detected.
+      clear: If True the existing logcat output will be cleared, defaults to
+          false.
+
+    Raises:
+      pexpect.TIMEOUT upon the timeout specified by StartMonitoringLogcat().
+
+    Returns:
+      The re match object if |success_re| is matched first or None if |error_re|
+      is matched first.
+    """
+    logging.info('<<< Waiting for logcat:' + str(success_re.pattern))
+    t0 = time.time()
+    while True:
+      if not self._logcat:
+        self.StartMonitoringLogcat(clear)
+      try:
+        while True:
+          # Note this will block for upto the timeout _per log line_, so we need
+          # to calculate the overall timeout remaining since t0.
+          time_remaining = t0 + self._logcat.timeout - time.time()
+          if time_remaining < 0: raise pexpect.TIMEOUT(self._logcat)
+          self._logcat.expect(PEXPECT_LINE_RE, timeout=time_remaining)
+          line = self._logcat.match.group(1)
+          if error_re:
+            error_match = error_re.search(line)
+            if error_match:
+              return None
+          success_match = success_re.search(line)
+          if success_match:
+            return success_match
+          logging.info('<<< Skipped Logcat Line:' + str(line))
+      except pexpect.TIMEOUT:
+        raise pexpect.TIMEOUT(
+            'Timeout (%ds) exceeded waiting for pattern "%s" (tip: use -vv '
+            'to debug)' %
+            (self._logcat.timeout, success_re.pattern))
+      except pexpect.EOF:
+        # It seems that sometimes logcat can end unexpectedly. This seems
+        # to happen during Chrome startup after a reboot followed by a cache
+        # clean. I don't understand why this happens, but this code deals with
+        # getting EOF in logcat.
+        logging.critical('Found EOF in adb logcat. Restarting...')
+        # Rerun spawn with original arguments. Note that self._logcat.args[0] is
+        # the path of adb, so we don't want it in the arguments.
+        self._logcat = pexpect.spawn('adb',
+                                     self._logcat.args[1:],
+                                     timeout=self._logcat.timeout,
+                                     logfile=self._logcat.logfile)
+
+  def StartRecordingLogcat(self, clear=True, filters=['*:v']):
+    """Starts recording logcat output to eventually be saved as a string.
+
+    This call should come before some series of tests are run, with either
+    StopRecordingLogcat or SearchLogcatRecord following the tests.
+
+    Args:
+      clear: True if existing log output should be cleared.
+      filters: A list of logcat filters to be used.
+    """
+    if clear:
+      self._adb.SendCommand('logcat -c')
+    logcat_command = 'adb %s logcat -v threadtime %s' % (self._adb._target_arg,
+                                                         ' '.join(filters))
+    self.logcat_process = subprocess.Popen(logcat_command, shell=True,
+                                           stdout=subprocess.PIPE)
+
+  def StopRecordingLogcat(self):
+    """Stops an existing logcat recording subprocess and returns output.
+
+    Returns:
+      The logcat output as a string or an empty string if logcat was not
+      being recorded at the time.
+    """
+    if not self.logcat_process:
+      return ''
+    # Cannot evaluate directly as 0 is a possible value.
+    # Better to read the self.logcat_process.stdout before killing it,
+    # Otherwise the communicate may return incomplete output due to pipe break.
+    if self.logcat_process.poll() is None:
+      self.logcat_process.kill()
+    (output, _) = self.logcat_process.communicate()
+    self.logcat_process = None
+    return output
+
+  def SearchLogcatRecord(self, record, message, thread_id=None, proc_id=None,
+                         log_level=None, component=None):
+    """Searches the specified logcat output and returns results.
+
+    This method searches through the logcat output specified by record for a
+    certain message, narrowing results by matching them against any other
+    specified criteria.  It returns all matching lines as described below.
+
+    Args:
+      record: A string generated by Start/StopRecordingLogcat to search.
+      message: An output string to search for.
+      thread_id: The thread id that is the origin of the message.
+      proc_id: The process that is the origin of the message.
+      log_level: The log level of the message.
+      component: The name of the component that would create the message.
+
+    Returns:
+      A list of dictionaries represeting matching entries, each containing keys
+      thread_id, proc_id, log_level, component, and message.
+    """
+    if thread_id:
+      thread_id = str(thread_id)
+    if proc_id:
+      proc_id = str(proc_id)
+    results = []
+    reg = re.compile('(\d+)\s+(\d+)\s+([A-Z])\s+([A-Za-z]+)\s*:(.*)$',
+                     re.MULTILINE)
+    log_list = reg.findall(record)
+    for (tid, pid, log_lev, comp, msg) in log_list:
+      if ((not thread_id or thread_id == tid) and
+          (not proc_id or proc_id == pid) and
+          (not log_level or log_level == log_lev) and
+          (not component or component == comp) and msg.find(message) > -1):
+        match = dict({'thread_id': tid, 'proc_id': pid,
+                      'log_level': log_lev, 'component': comp,
+                      'message': msg})
+        results.append(match)
+    return results
+
+  def ExtractPid(self, process_name):
+    """Extracts Process Ids for a given process name from Android Shell.
+
+    Args:
+      process_name: name of the process on the device.
+
+    Returns:
+      List of all the process ids (as strings) that match the given name.
+      If the name of a process exactly matches the given name, the pid of
+      that process will be inserted to the front of the pid list.
+    """
+    pids = []
+    for line in self.RunShellCommand('ps', log_result=False):
+      data = line.split()
+      try:
+        if process_name in data[-1]:  # name is in the last column
+          if process_name == data[-1]:
+            pids.insert(0, data[1])  # PID is in the second column
+          else:
+            pids.append(data[1])
+      except IndexError:
+        pass
+    return pids
+
+  def GetIoStats(self):
+    """Gets cumulative disk IO stats since boot (for all processes).
+
+    Returns:
+      Dict of {num_reads, num_writes, read_ms, write_ms} or None if there
+      was an error.
+    """
+    for line in self.GetFileContents('/proc/diskstats', log_result=False):
+      stats = io_stats_parser.ParseIoStatsLine(line)
+      if stats.device == 'mmcblk0':
+        return {
+            'num_reads': stats.num_reads_issued,
+            'num_writes': stats.num_writes_completed,
+            'read_ms': stats.ms_spent_reading,
+            'write_ms': stats.ms_spent_writing,
+        }
+    logging.warning('Could not find disk IO stats.')
+    return None
+
+  def GetMemoryUsageForPid(self, pid):
+    """Returns the memory usage for given pid.
+
+    Args:
+      pid: The pid number of the specific process running on device.
+
+    Returns:
+      A tuple containg:
+      [0]: Dict of {metric:usage_kb}, for the process which has specified pid.
+      The metric keys which may be included are: Size, Rss, Pss, Shared_Clean,
+      Shared_Dirty, Private_Clean, Private_Dirty, Referenced, Swap,
+      KernelPageSize, MMUPageSize, Nvidia (tablet only).
+      [1]: Detailed /proc/[PID]/smaps information.
+    """
+    usage_dict = collections.defaultdict(int)
+    smaps = collections.defaultdict(dict)
+    current_smap = ''
+    for line in self.GetFileContents('/proc/%s/smaps' % pid, log_result=False):
+      items = line.split()
+      # See man 5 proc for more details. The format is:
+      # address perms offset dev inode pathname
+      if len(items) > 5:
+        current_smap = ' '.join(items[5:])
+      elif len(items) > 3:
+        current_smap = ' '.join(items[3:])
+      match = re.match(MEMORY_INFO_RE, line)
+      if match:
+        key = match.group('key')
+        usage_kb = int(match.group('usage_kb'))
+        usage_dict[key] += usage_kb
+        if key not in smaps[current_smap]:
+          smaps[current_smap][key] = 0
+        smaps[current_smap][key] += usage_kb
+    if not usage_dict or not any(usage_dict.values()):
+      # Presumably the process died between ps and calling this method.
+      logging.warning('Could not find memory usage for pid ' + str(pid))
+
+    for line in self.GetFileContents('/d/nvmap/generic-0/clients',
+                                     log_result=False):
+      match = re.match(NVIDIA_MEMORY_INFO_RE, line)
+      if match and match.group('pid') == pid:
+        usage_bytes = int(match.group('usage_bytes'))
+        usage_dict['Nvidia'] = int(round(usage_bytes / 1000.0))  # kB
+        break
+
+    return (usage_dict, smaps)
+
+  def GetMemoryUsageForPackage(self, package):
+    """Returns the memory usage for all processes whose name contains |pacakge|.
+
+    Args:
+      package: A string holding process name to lookup pid list for.
+
+    Returns:
+      A tuple containg:
+      [0]: Dict of {metric:usage_kb}, summed over all pids associated with
+           |name|.
+      The metric keys which may be included are: Size, Rss, Pss, Shared_Clean,
+      Shared_Dirty, Private_Clean, Private_Dirty, Referenced, Swap,
+      KernelPageSize, MMUPageSize, Nvidia (tablet only).
+      [1]: a list with detailed /proc/[PID]/smaps information.
+    """
+    usage_dict = collections.defaultdict(int)
+    pid_list = self.ExtractPid(package)
+    smaps = collections.defaultdict(dict)
+
+    for pid in pid_list:
+      usage_dict_per_pid, smaps_per_pid = self.GetMemoryUsageForPid(pid)
+      smaps[pid] = smaps_per_pid
+      for (key, value) in usage_dict_per_pid.items():
+        usage_dict[key] += value
+
+    return usage_dict, smaps
+
+  def ProcessesUsingDevicePort(self, device_port):
+    """Lists processes using the specified device port on loopback interface.
+
+    Args:
+      device_port: Port on device we want to check.
+
+    Returns:
+      A list of (pid, process_name) tuples using the specified port.
+    """
+    tcp_results = self.RunShellCommand('cat /proc/net/tcp', log_result=False)
+    tcp_address = '0100007F:%04X' % device_port
+    pids = []
+    for single_connect in tcp_results:
+      connect_results = single_connect.split()
+      # Column 1 is the TCP port, and Column 9 is the inode of the socket
+      if connect_results[1] == tcp_address:
+        socket_inode = connect_results[9]
+        socket_name = 'socket:[%s]' % socket_inode
+        lsof_results = self.RunShellCommand('lsof', log_result=False)
+        for single_process in lsof_results:
+          process_results = single_process.split()
+          # Ignore the line if it has less than nine columns in it, which may
+          # be the case when a process stops while lsof is executing.
+          if len(process_results) <= 8:
+            continue
+          # Column 0 is the executable name
+          # Column 1 is the pid
+          # Column 8 is the Inode in use
+          if process_results[8] == socket_name:
+            pids.append((int(process_results[1]), process_results[0]))
+        break
+    logging.info('PidsUsingDevicePort: %s', pids)
+    return pids
+
+  def FileExistsOnDevice(self, file_name):
+    """Checks whether the given file exists on the device.
+
+    Args:
+      file_name: Full path of file to check.
+
+    Returns:
+      True if the file exists, False otherwise.
+    """
+    assert '"' not in file_name, 'file_name cannot contain double quotes'
+    status = self._adb.SendShellCommand(
+        '\'test -e "%s"; echo $?\'' % (file_name))
+    if 'test: not found' not in status:
+      return int(status) == 0
+
+    status = self._adb.SendShellCommand(
+        '\'ls "%s" >/dev/null 2>&1; echo $?\'' % (file_name))
+    return int(status) == 0
+
+
+class NewLineNormalizer(object):
+  """A file-like object to normalize EOLs to '\n'.
+
+  Pexpect runs adb within a pseudo-tty device (see
+  http://www.noah.org/wiki/pexpect), so any '\n' printed by adb is written
+  as '\r\n' to the logfile. Since adb already uses '\r\n' to terminate
+  lines, the log ends up having '\r\r\n' at the end of each line. This
+  filter replaces the above with a single '\n' in the data stream.
+  """
+  def __init__(self, output):
+    self._output = output
+
+  def write(self, data):
+    data = data.replace('\r\r\n', '\n')
+    self._output.write(data)
+
+  def flush(self):
+    self._output.flush()
+