web_dev_style: Fix errors in new directories and enable PRESUBMIT

components/flags_ui/PRESUBMIT.py

Index: components/flags_ui/PRESUBMIT.py
diff --git a/components/flags_ui/PRESUBMIT.py b/components/flags_ui/PRESUBMIT.py
new file mode 100644
index 0000000000000000000000000000000000000000..469f90770159f681b15e86353abbc3a256b36af7
--- /dev/null
+++ b/components/flags_ui/PRESUBMIT.py
@@ -0,0 +1,25 @@
+# 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.
+
+
+def _CommonChecks(input_api, output_api):
+  results = []
+  try:
+    import sys
+    old_sys_path = sys.path
+    cwd = input_api.PresubmitLocalPath()
+    sys.path += [input_api.os_path.join(cwd, '..', '..', 'tools')]
+    import web_dev_style.presubmit_support
+    results += web_dev_style.presubmit_support.CheckStyle(input_api, output_api)
+  finally:
+    sys.path = old_sys_path
+  return results
+
+
+def CheckChangeOnUpload(input_api, output_api):
+  return _CommonChecks(input_api, output_api)
+
+
+def CheckChangeOnCommit(input_api, output_api):
+  return _CommonChecks(input_api, output_api)