https://build.chromium.org/p/chromium/builders/Linux%20x64/builds/47590

Traceback (most recent call last):
  File "/b/c/b/linux_clobber/src/testing/scripts/sizes.py", line 113, in <module>
    sys.exit(common.run_script(sys.argv[1:], funcs))
  File "/b/c/b/linux_clobber/src/testing/scripts/common.py", line 66, in run_script
    return args.func(args)
  File "/b/c/b/linux_clobber/src/testing/scripts/sizes.py", line 51, in main_run
    rc = common.run_runtest(args, runtest_args + sizes_cmd)
  File "/b/c/b/linux_clobber/src/testing/scripts/common.py", line 95, in run_runtest
    if cmd_args.use_src_side_runtest_py:
AttributeError: 'Namespace' object has no attribute 'use_src_side_runtest_py'
step returned non-zero exit code: 1

Reverted https://chromium-review.googlesource.com/c/chromium/src/+/640430/

Thanks for reverting this & sorry about the hassle.