Vulcanize MD History to improve page-load performance

chrome/browser/resources/md_history/PRESUBMIT.py

+# Copyright 2016 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 CheckChangeOnUpload(input_api, output_api):
+  """Warn when changing md_history without vulcanizing."""
+
+  def _is_md_history_file(path):
+    return (path.startswith('chrome/browser/resources/md_history') and
+            (not path.endswith('externs.js')) and
+            (path.endswith('js') or path.endswith('html')))
+
+  def _affects_file(filename, paths):
+    return any([filename in path for path in paths])
+
+  paths = [x.LocalPath() for x in input_api.change.AffectedFiles()]
+  vulcanize_changes = (_affects_file('md_history/app.vulcanized.html', paths) or
+                       _affects_file('md_history/app.crisper.js', paths))
+  history_changes = filter(_is_md_history_file, paths)
+
+  if history_changes and not vulcanize_changes:
+    return [output_api.PresubmitPromptWarning(
+        'Vulcanize must be run when changing files in md_history. See '
+        'docs/vulcanize.md.')]
+  return []