Sync to latest from aosp master

bug:22636165

Change-Id: Iccf99b34047273f277eae53ef9614e3e562ece4d
diff --git a/util.py b/util.py
new file mode 100644
index 0000000..5fb61a8
--- /dev/null
+++ b/util.py
@@ -0,0 +1,115 @@
+# Copyright (c) 2015 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 optparse
+import subprocess
+import sys
+
+
+class OptionParserIgnoreErrors(optparse.OptionParser):
+  """Wrapper for OptionParser that ignores errors and produces no output."""
+
+  def error(self, msg):
+    pass
+
+  def exit(self):
+    pass
+
+  def print_usage(self):
+    pass
+
+  def print_help(self):
+    pass
+
+  def print_version(self):
+    pass
+
+
+def add_adb_serial(adb_command, device_serial):
+  if device_serial is not None:
+    adb_command.insert(1, device_serial)
+    adb_command.insert(1, '-s')
+
+
+def construct_adb_shell_command(shell_args, device_serial):
+  adb_command = ['adb', 'shell', ' '.join(shell_args)]
+  add_adb_serial(adb_command, device_serial)
+  return adb_command
+
+
+def run_adb_shell(shell_args, device_serial):
+  """Runs "adb shell" with the given arguments.
+
+  Args:
+    shell_args: array of arguments to pass to adb shell.
+    device_serial: if not empty, will add the appropriate command-line
+        parameters so that adb targets the given device.
+  Returns:
+    A tuple containing the adb output (stdout & stderr) and the return code
+    from adb.  Will exit if adb fails to start.
+  """
+  adb_command = construct_adb_shell_command(shell_args, device_serial)
+
+  adb_output = []
+  adb_return_code = 0
+  try:
+    adb_output = subprocess.check_output(adb_command, stderr=subprocess.STDOUT,
+                                         shell=False, universal_newlines=True)
+  except OSError as error:
+    # This usually means that the adb executable was not found in the path.
+    print >> sys.stderr, ('\nThe command "%s" failed with the following error:'
+                          % ' '.join(adb_command))
+    print >> sys.stderr, '    %s\n' % str(error)
+    print >> sys.stderr, 'Is adb in your path?'
+    sys.exit(1)
+  except subprocess.CalledProcessError as error:
+    # The process exited with an error.
+    adb_return_code = error.returncode
+    adb_output = error.output
+
+  return (adb_output, adb_return_code)
+
+
+def get_device_sdk_version():
+  """Uses adb to attempt to determine the SDK version of a running device."""
+
+  getprop_args = ['getprop', 'ro.build.version.sdk']
+
+  # get_device_sdk_version() is called before we even parse our command-line
+  # args.  Therefore, parse just the device serial number part of the
+  # command-line so we can send the adb command to the correct device.
+  parser = OptionParserIgnoreErrors()
+  parser.add_option('-e', '--serial', dest='device_serial', type='string')
+  options, unused_args = parser.parse_args()
+
+  success = False
+
+  adb_output, adb_return_code = run_adb_shell(getprop_args,
+                                              options.device_serial)
+
+  if adb_return_code == 0:
+    # ADB may print output other than the version number (e.g. it chould
+    # print a message about starting the ADB server).
+    # Break the ADB output into white-space delimited segments.
+    parsed_output = str.split(adb_output)
+    if parsed_output:
+      # Assume that the version number is the last thing printed by ADB.
+      version_string = parsed_output[-1]
+      if version_string:
+        try:
+          # Try to convert the text into an integer.
+          version = int(version_string)
+        except ValueError:
+          version = -1
+        else:
+          success = True
+
+  if not success:
+    print >> sys.stderr, (
+        '\nThe command "%s" failed with the following message:'
+        % ' '.join(getprop_args))
+    print >> sys.stderr, adb_output
+    sys.exit(1)
+
+  return version