Update from https://crrev.com/327068

build/android/enable_asserts.py

Index: build/android/enable_asserts.py
diff --git a/build/android/enable_asserts.py b/build/android/enable_asserts.py
index 0e30bc2a1736d529511b038007f6e9bc707c2b7e..8fb7dca4725fe884af73115b0751d68d74f99940 100755
--- a/build/android/enable_asserts.py
+++ b/build/android/enable_asserts.py
@@ -6,33 +6,37 @@
 
 """Enables dalvik vm asserts in the android device."""
 
-from pylib import android_commands
-from pylib.device import device_utils
-import optparse
+import argparse
 import sys
 
+from pylib.device import device_utils
+
+
+def main():
+  parser = argparse.ArgumentParser()
 
-def main(argv):
-  option_parser = optparse.OptionParser()
-  option_parser.add_option('--enable_asserts', dest='set_asserts',
-      action='store_true', default=None,
+  set_asserts_group = parser.add_mutually_exclusive_group(required=True)
+  set_asserts_group.add_argument(
+      '--enable_asserts', dest='set_asserts', action='store_true',
       help='Sets the dalvik.vm.enableassertions property to "all"')
-  option_parser.add_option('--disable_asserts', dest='set_asserts',
-      action='store_false', default=None,
+  set_asserts_group.add_argument(
+      '--disable_asserts', dest='set_asserts', action='store_false',
       help='Removes the dalvik.vm.enableassertions property')
-  options, _ = option_parser.parse_args(argv)
+
+  args = parser.parse_args()
 
   # TODO(jbudorick): Accept optional serial number and run only for the
   # specified device when present.
-  devices = android_commands.GetAttachedDevices()
-  for device in [device_utils.DeviceUtils(serial) for serial in devices]:
-    if options.set_asserts != None:
-      if device.SetJavaAsserts(options.set_asserts):
-        # TODO(jbudorick) How to best do shell restarts after the
-        #                 android_commands refactor?
-        device.RunShellCommand('stop')
-        device.RunShellCommand('start')
+  devices = device_utils.DeviceUtils.parallel()
+
+  def set_java_asserts_and_restart(device):
+    if device.SetJavaAsserts(args.set_asserts):
+      device.RunShellCommand('stop')
+      device.RunShellCommand('start')
+
+  devices.pMap(set_java_asserts_and_restart)
+  return 0
 
 
 if __name__ == '__main__':
-  main(sys.argv)
+  sys.exit(main())