Add everything from src/tools/isolate r159537.

tests/trace_inputs/touch_only.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.
+
+"""Uses different APIs to touch a file."""
+
+import os
+import sys
+
+
+BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
+def main():
+  print 'Only look if a file exists but do not open it.'
+  assert len(sys.argv) == 2
+  path = os.path.join(BASE_DIR, 'test_file.txt')
+  command = sys.argv[1]
+  if command == 'access':
+    return not os.access(path, os.R_OK)
+  elif command == 'isfile':
+    return not os.path.isfile(path)
+  elif command == 'stat':
+    return not os.stat(path).st_size
+  return 1
+
+
+if __name__ == '__main__':
+  sys.exit(main())