Add a new script to upload perf tests.

Also add a script to do the bridge between a python 2 and a python 3 interpreter.
This should be removed when the merge scripts will be using python 3 (https://crbug.com/webrtc/13835).

Note that webrtc_dashboard_upload.py will be removed when the new script is stabilized.

Bug: webrtc:13806
Change-Id: I806fa11f417ef37674bdaeb5126c71570e3697d7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/255560
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Christoffer Jansson <jansson@google.com>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Christoffer Jansson <jansson@webrtc.org>
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Cr-Commit-Position: refs/heads/main@{#36252}

tools_webrtc/perf/process_perf_results_py2.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env vpython3
+
+# Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+"""Calls process_perf_results.py with a python 3 interpreter."""
+
+import sys
+import subprocess
+
+
+# TODO(crbug.com/webrtc/13835): Delete this file and use
+# process_perf_results.py instead.
+def main():
+  cmd = sys.argv[0].replace('_py2', '')
+  print('Calling "%s" with py3 in case this script was called with py2.' % cmd)
+  return subprocess.call(['vpython3', cmd] + sys.argv[1:])
+
+
+if __name__ == '__main__':
+  sys.exit(main())