Fix build/android/enable_asserts.py.

The script seems to have been broken in
https://codereview.chromium.org/221823011 (missing device serial when
creating DeviceUtils).

This fixes the script by iterating over all connected devices.

BUG=267773

Review URL: https://codereview.chromium.org/249533002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@265770 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/enable_asserts.py

@@ -6,6 +6,7 @@
 
 """Enables dalvik vm asserts in the android device."""
 
+from pylib import android_commands
 from pylib.device import device_utils
 import optparse
 import sys
@@ -21,10 +22,13 @@ def main(argv):
       help='Removes the dalvik.vm.enableassertions property')
   options, _ = option_parser.parse_args(argv)
 
-  device = device_utils.DeviceUtils()
-  if options.set_asserts != None:
-    if device.old_interface.SetJavaAssertsEnabled(options.set_asserts):
-      device.old_interface.Reboot(full_reboot=False)
+  # 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.old_interface.SetJavaAssertsEnabled(options.set_asserts):
+        device.old_interface.Reboot(full_reboot=False)
 
 
 if __name__ == '__main__':