The expected behavior is to have something similar than python: https://docs.python.org/dev/library/argparse.html#dest: "Any internal - characters will be converted to _ characters to make sure the string is a valid attribute name". This allows to catch chromium arguments like 'isolated-script-test-output' that previously needed some preprocessing done for example in flags_compatibility.py. This CL also fixes a fuchsia specific issue where the test runner needs a 'isolated-script-test-output' argument but then pass the argument to WebRTC that expects a 'isolated_script_test_output' argument. Thus calling flags_compatibility before the test_runner fails and there is not much room to change the argument in between the test runner and the test. Change-Id: I48a591743fa50484a0ec584a3f9e97d9e0fd25ef Bug: webrtc:14694 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/284541 Commit-Queue: Jeremy Leconte <jleconte@google.com> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/main@{#38707}