[Telemetry] Refactor common Android cleanup functions.

build/android/pylib/utils/test_environment.py

+# Copyright (c) 2013 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 logging
+import os
+import psutil
+
+from pylib import android_commands
+from pylib import ports
+
+def _KillWebServers():
+  for retry in xrange(5):
+    for server in ['lighttpd', 'web-page-replay']:
+      pids = [p.pid for p in psutil.process_iter() if server in p.name]
+      for pid in pids:
+        try:
+          logging.warning('Killing %s %s', server, pid)
+          os.kill(pid, signal.SIGQUIT)
+        except Exception as e:
+          logging.warning('Failed killing %s %s %s', server, pid, e)
+
+
+def CleanupLeftoverProcesses():
+  """Clean up the test environment, restarting fresh adb and HTTP daemons."""
+  _KillWebServers()
+  did_restart_host_adb = False
+  for device in android_commands.GetAttachedDevices():
+    adb = android_commands.AndroidCommands(device)
+    # Make sure we restart the host adb server only once.
+    if not did_restart_host_adb:
+      adb.RestartAdbServer()
+      did_restart_host_adb = True
+    adb.RestartAdbdOnDevice()
+    adb.EnableAdbRoot()
+    adb.WaitForDevicePm()