[ios] Remove unused script

This is a remnant from building with xcodebuild/gyp.
Can safely be removed as it is unused.

Bug: None
Change-Id: I501146d14d2b1256180d1d3db40592019c0e5cf2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2270061
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Olivier Robin <olivierrobin@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784360}

build/ios/clean_env.py

-#!/usr/bin/env python
-# Copyright (c) 2012 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
-import sys
-
-def Main(argv):
-  """This is like 'env -i', but it uses a whitelist of env variables to allow
-  through to the command being run.  It attempts to strip off Xcode-added
-  values from PATH.
-  """
-  # Note: An attempt was made to do something like: env -i bash -lc '[command]'
-  # but that fails to set the things set by login (USER, etc.), so instead
-  # the only approach that seems to work is to have a whitelist.
-  env_key_whitelist = (
-    'HOME',
-    'LOGNAME',
-    # 'PATH' added below (but filtered).
-    'PWD',
-    'SHELL',
-    'TEMP',
-    'TMPDIR',
-    'USER'
-  )
-
-  # Need something to run.
-  # TODO(lliabraa): Make this output a usage string and exit (here and below).
-  assert(len(argv) > 0)
-
-  add_to_path = [];
-  first_entry = argv[0];
-  if first_entry.startswith('ADD_TO_PATH='):
-    argv = argv[1:];
-    add_to_path = first_entry.replace('ADD_TO_PATH=', '', 1).split(':')
-
-  # Still need something to run.
-  assert(len(argv) > 0)
-
-  clean_env = {}
-
-  # Pull over the whitelisted keys.
-  for key in env_key_whitelist:
-    val = os.environ.get(key, None)
-    if not val is None:
-      clean_env[key] = val
-
-  # Collect the developer dir as set via Xcode, defaulting it.
-  dev_prefix = os.environ.get('DEVELOPER_DIR', '/Developer/')
-  if dev_prefix[-1:] != '/':
-    dev_prefix += '/'
-
-  # Now pull in PATH, but remove anything Xcode might have added.
-  initial_path = os.environ.get('PATH', '')
-  filtered_chunks = \
-      [x for x in initial_path.split(':') if not x.startswith(dev_prefix)]
-  if filtered_chunks:
-    clean_env['PATH'] = ':'.join(add_to_path + filtered_chunks)
-
-  # Add any KEY=VALUE args before the command to the cleaned environment.
-  args = argv[:]
-  while '=' in args[0]:
-    (key, val) = args[0].split('=', 1)
-    clean_env[key] = val
-    args = args[1:]
-
-  # Still need something to run.
-  assert(len(args) > 0)
-
-  # Off it goes...
-  os.execvpe(args[0], args, clean_env)
-  # Should never get here, so return a distinctive, non-zero status code.
-  return 66
-
-if __name__ == '__main__':
-  sys.exit(Main(sys.argv[1:]))