[Android] Switch to DeviceUtils versions of file functions.

build/android/tombstones.py

 #!/usr/bin/env python
 #
 # Copyright 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.
 #
 # Find the most recent tombstone file(s) on all connected devices
 # and prints their stacks.
 #
 # Assumes tombstone file was created with current symbols.
@@ skipping 44 matching lines @@
 def _GetTombstoneData(device, tombstone_file):
   """Retrieve the tombstone data from the device
 
   Args:
     device: An instance of DeviceUtils.
     tombstone_file: the tombstone to retrieve
 
   Returns:
     A list of lines
   """
-  return device.old_interface.GetProtectedFileContents(
-      '/data/tombstones/' + tombstone_file)
+  return device.ReadFile('/data/tombstones/' + tombstone_file, as_root=True)
 
 
 def _EraseTombstone(device, tombstone_file):
   """Deletes a tombstone from the device.
 
   Args:
     device: An instance of DeviceUtils.
     tombstone_file: the tombstone to delete.
   """
   return device.RunShellCommand(
@@ skipping 113 matching lines @@
 
   tombstones = []
   for device_serial in devices:
     device = device_utils.DeviceUtils(device_serial)
     tombstones += _GetTombstonesForDevice(device, options)
 
   _ResolveTombstones(options.jobs, tombstones)
 
 if __name__ == '__main__':
   sys.exit(main())