Add fetch-config for v8-perf repo

Based on the existing v8.py config.

Change-Id: I58089e1d899fe4dcc09d259a0ab77a893d0907ea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6684932
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Brian Ryner <bryner@google.com>

fetch_configs/v8_perf.py

@@ -0,0 +1,43 @@
+# Copyright 2025 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 V8Perf(config_util.Config):
+    """Basic Config class for V8-Perf."""
+
+    @staticmethod
+    def fetch_spec(props):
+        url = 'https://chrome-internal.googlesource.com/v8/v8-perf.git'
+        solution = {
+            'name': 'v8-perf',
+            'url': url,
+            'deps_file': 'DEPS',
+            'managed': False,
+            'custom_deps': {},
+        }
+        spec = {
+            'solutions': [solution],
+        }
+        return {
+            'type': 'gclient_git',
+            'gclient_git_spec': spec,
+        }
+
+    @staticmethod
+    def expected_root(_props):
+        return 'v8-perf'
+
+
+def main(argv=None):
+    return V8Perf().handle_args(argv)
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))