Adding check for team and component tags in owners files.

tools/checkteamtags/PRESUBMIT.py

Index: tools/checkteamtags/PRESUBMIT.py
diff --git a/tools/checkteamtags/PRESUBMIT.py b/tools/checkteamtags/PRESUBMIT.py
new file mode 100644
index 0000000000000000000000000000000000000000..542eb1f622feaafd180df83cf49ca59f4b44859b
--- /dev/null
+++ b/tools/checkteamtags/PRESUBMIT.py
@@ -0,0 +1,46 @@
+# Copyright (c) 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.
+
+"""Top-level presubmit script for checkteamtags
+
+See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
+details on the presubmit API.
+"""
+
+import subprocess
+
+
+def CheckChangeOnUpload(input_api, output_api):
+  return _CommonChecks(input_api, output_api)
+
+
+def CheckChangeOnCommit(input_api, output_api):
+  return _CommonChecks(input_api, output_api)
+
+
+def _CommonChecks(input_api, output_api):
+  """Does all presubmit checks for chekteamtags."""
+  results = []
+  results.extend(_RunUnitTests(input_api, output_api))
+  results.extend(_RunPyLint(input_api, output_api))
+  return results
+
+def _RunUnitTests(input_api, output_api):
+  """Runs unit tests for checkteamtags."""
+  repo_root = input_api.change.RepositoryRoot()
+  checkteamtags_dir = input_api.os_path.join(repo_root, 'tools',
+                                             'checkteamtags')
+  test_runner = input_api.os_path.join(checkteamtags_dir, 'run_tests')
+  return_code = subprocess.call(['python', test_runner])
+  if return_code:
+    message = 'Checkteamtags unit tests did not all pass.'
+    return [output_api.PresubmitError(message)]
+  return []
+
+
+def _RunPyLint(input_api, output_api):
+  """Runs unit tests for checkteamtags."""
+  tests = input_api.canned_checks.GetPylint(
+      input_api, output_api)
+  return input_api.RunTests(tests)