add "fetch goma_client"

Change-Id: I738c566be04a4ba2f699c1cbe2a8d1f43c2c0e93
Reviewed-on: https://chromium-review.googlesource.com/856616Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Mostyn Bramley-Moore <mostynb@vewd.com>

fetch_configs/goma_client.py

+# Copyright 2018 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 GomaClient(config_util.Config):
+  """Basic Config class for Goma client."""
+
+  @staticmethod
+  def fetch_spec(_props):
+    return {
+      'type': 'gclient_git',
+      'gclient_git_spec': {
+        'solutions': [
+          {
+            'name'     : 'client',
+            'url'      : 'https://chromium.googlesource.com/infra/goma/client.git',
+            'deps_file': 'DEPS',
+            'managed'  : False,
+          }
+        ],
+      },
+    }
+
+  @staticmethod
+  def expected_root(_props):
+    return 'client'
+
+
+def main(argv=None):
+  return GomaClient().handle_args(argv)
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))