Add everything from src/tools/isolate r159537.

tests/trace_inputs/symlink.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():
+  print 'symlink: touches files2/'
+  assert len(sys.argv) == 1
+
+  expected = {
+    'bar': 'Foo\n',
+    'foo': 'Bar\n',
+  }
+
+  if not os.path.basename(os.getcwd()) == 'tests':
+    print 'Start this script from inside "tests"'
+    return 1
+
+  root = os.path.join('trace_inputs', 'files2')
+  actual = dict(
+      (filename, open(os.path.join(root, filename), 'rb').read())
+      for filename in (os.listdir(root)))
+
+  if actual != expected:
+    print 'Failure'
+    print actual
+    print expected
+    return 2
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())