Revert of (reland) Check missing headers in the build on CQ

testing/scripts/check_gn_headers.py

-#!/usr/bin/env python
-# Copyright 2017 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 json
-import os
-import sys
-
-
-import common
-
-
-def main_run(args):
-  with common.temporary_file() as tempfile_path:
-    rc = common.run_command([
-        sys.executable,
-        os.path.join(common.SRC_DIR, 'build', 'check_gn_headers.py'),
-        '--out-dir',
-        os.path.join(args.paths['checkout'], 'out', args.build_config_fs),
-        '--whitelist',
-        os.path.join(common.SRC_DIR, 'build', 'check_gn_headers_whitelist.txt'),
-        '--json', tempfile_path
-    ], cwd=common.SRC_DIR)
-
-    with open(tempfile_path) as f:
-      failures = json.load(f)
-
-  json.dump({
-      'valid': True,
-      'failures': failures,
-  }, args.output)
-
-  return rc
-
-
-def main_compile_targets(args):
-  json.dump([], args.output)
-
-
-if __name__ == '__main__':
-  funcs = {
-    'run': main_run,
-    'compile_targets': main_compile_targets,
-  }
-  sys.exit(common.run_script(sys.argv[1:], funcs))