Add PRESUBMIT check to enforce the rule of tools/perf/contrib/ directory

tools/perf/contrib/PRESUBMIT.py

Index: tools/perf/contrib/PRESUBMIT.py
diff --git a/tools/perf/contrib/PRESUBMIT.py b/tools/perf/contrib/PRESUBMIT.py
new file mode 100644
index 0000000000000000000000000000000000000000..38f2a046b110ce458a9f784cf1ad406f17e23e57
--- /dev/null
+++ b/tools/perf/contrib/PRESUBMIT.py
@@ -0,0 +1,75 @@
+# 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):
+  """Performs common checks, which includes running pylint."""
+  results = []
+
+  results.extend(_CheckContribDir(input_api, output_api))
+  return results
+
+
+def _CheckOwnershipForContribSubDir(sub_dir, input_api, output_api):
+  results = []
+  owner_file = input_api.os_path.join(sub_dir, 'OWNERS')
+  if not input_api.os_path.isfile(owner_file):
+    results.append(output_api.PresubmitError(
+        '%s must have an OWNERS file' % sub_dir))
+  else:
+    owners = []
+    with open(owner_file) as f:
+      for line in f:
+        if line.strip() and not line.strip().startswith('#'):
+          owners.append(line)
+    if len(owners) < 2:
+      results.append(output_api.PresubmitError(
+          '%s must have at least 2 owners' % owner_file))
+  return results
+
+
+def _CheckContribDir(input_api, output_api):
+  """ Check to make sure that:
+    1) tools/perf/contrib/ contains only directories, except __init__.py,
+    README.md, and PRESUBMIT.py file
+    2) Every subdirectory in tools/perf/contrib/ must have an OWNERS file with
+    at least two OWNERS.
+  """
+  results = []
+  contrib_dir = input_api.PresubmitLocalPath()
+  init = input_api.os_path.join(contrib_dir, '__init__.py')
+  readme = input_api.os_path.join(contrib_dir, 'README.md')
+  presubmit = input_api.os_path.join(contrib_dir, 'PRESUBMIT.py')
+
+  invalid_contrib_files = []
+  for f in input_api.AffectedFiles(include_deletes=False):
+    file_path = f.AbsoluteLocalPath()
+    if (input_api.os_path.dirname(file_path) == contrib_dir and
+        not file_path in (init, readme, presubmit)):
+      invalid_contrib_files.append(file_path)
+
+  for f in input_api.os_listdir(contrib_dir):
+    path = input_api.os_path.join(contrib_dir, f)
+    if input_api.os_path.isdir(path):
+      results.extend(
+          _CheckOwnershipForContribSubDir(path, input_api, output_api))
+
+  if invalid_contrib_files:
+    results.append(output_api.PresubmitError(
+        'You cannot add files to top level of contrib directory. '
+        'Please moves these files to a sub directory:\n %s' %
+        '\n'.join(invalid_contrib_files)))
+  return results
+
+
+def CheckChangeOnUpload(input_api, output_api):
+  report = []
+  report.extend(_CommonChecks(input_api, output_api))
+  return report
+
+
+def CheckChangeOnCommit(input_api, output_api):
+  report = []
+  report.extend(_CommonChecks(input_api, output_api))
+  return report