Reland of Android: Trust large random numbers for temp files

build/android/provision_devices.py

 #!/usr/bin/env python
 #
 # 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.
 
 """Provisions Android devices with settings required for bots.
 
 Usage:
   ./provision_devices.py [-d <device serial number>]
@@ skipping 119 matching lines @@
     blacklist.Extend([str(device)])
 
 def CheckExternalStorage(device):
   """Checks that storage is writable and if not makes it writable.
 
   Arguments:
     device: The device to check.
   """
   try:
     with device_temp_file.DeviceTempFile(
-        device.adb, suffix='.sh', dir=device.GetExternalStoragePath()):
-      pass
+        device.adb, suffix='.sh', dir=device.GetExternalStoragePath()) as f:
+      device.WriteFile(f.name, 'test')
   except device_errors.CommandFailedError:
     logging.info('External storage not writable. Remounting / as RW')
     device.RunShellCommand(['mount', '-o', 'remount,rw', '/'],
                            check_return=True, as_root=True)
     device.EnableRoot()
     with device_temp_file.DeviceTempFile(
-        device.adb, suffix='.sh', dir=device.GetExternalStoragePath()):
-      pass
+        device.adb, suffix='.sh', dir=device.GetExternalStoragePath()) as f:
+      device.WriteFile(f.name, 'test')
 
 def WipeChromeData(device, options):
   """Wipes chrome specific data from device
 
   (1) uninstall any app whose name matches *chrom*, except
       com.android.chrome, which is the chrome stable package. Doing so also
       removes the corresponding dirs under /data/data/ and /data/app/
   (2) remove any dir under /data/app-lib/ whose name matches *chrom*
   (3) remove any files under /data/tombstones/ whose name matches "tombstone*"
   (4) remove /data/local.prop if there is any
@@ skipping 322 matching lines @@
   args = parser.parse_args()
   constants.SetBuildType(args.target)
 
   run_tests_helper.SetLogLevel(args.verbose)
 
   return ProvisionDevices(args)
 
 
 if __name__ == '__main__':
   sys.exit(main())