[Android] Remove chromium version of devil.

build/android/devil/utils/file_utils.py

-# Copyright 2016 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 os
-
-
-def MergeFiles(dest_file, source_files):
-  """Merge list of files into single destination file.
-
-  Args:
-    dest_file: File to be written to.
-    source_files: List of files to be merged. Will be merged in the order they
-        appear in the list.
-  """
-  if not os.path.exists(os.path.dirname(dest_file)):
-    os.makedirs(os.path.dirname(dest_file))
-  try:
-    with open(dest_file, 'w') as dest_f:
-      for source_file in source_files:
-        with open(source_file, 'r') as source_f:
-          dest_f.write(source_f.read())
-  except Exception as e:  # pylint: disable=broad-except
-    # Something went wrong when creating dest_file. Cleaning up.
-    try:
-      os.remove(dest_file)
-    except OSError:
-      pass
-    raise e
-
-