Add fetch config for infra_superproject.

Bug: 1421776
Change-Id: I7d2077d5b47fa62bebc334ee1758619851292158
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4358836
Reviewed-by: Gavin Mak <gavinmak@google.com>

fetch_configs/infra_superproject.py

@@ -0,0 +1,46 @@
+# Copyright 2023 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 sys
+
+import config_util  # pylint: disable=import-error
+
+
+# This class doesn't need an __init__ method, so we disable the warning
+# pylint: disable=no-init
+class InfraSuperproject(config_util.Config):
+  """Basic Config class for the whole set of Infrastructure repositories."""
+  @staticmethod
+  def fetch_spec(_props):
+    def url(host, repo):
+      return 'https://%s.googlesource.com/%s.git' % (host, repo)
+
+    spec = {
+        'solutions': [
+            {
+                'name': '.',
+                'url': url('chromium', 'infra/infra_superproject'),
+                'managed': False,
+                'custom_vars': {
+                    'checkout_internal': True
+                }
+            },
+        ],
+    }
+    return {
+        'type': 'gclient_git',
+        'gclient_git_spec': spec,
+    }
+
+  @staticmethod
+  def expected_root(_props):
+    return '.'
+
+
+def main(argv=None):
+  return InfraSuperproject().handle_args(argv)
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))