mac: Remove --xcode-version flag from mac_toolchain.py

No callers still pass this.

Bug: 1147839
Change-Id: Ie4600fbba9c13c84527ed7315fa3a4af22788d77
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2545096
Commit-Queue: Nico Weber <thakis@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828545}

build/mac_toolchain.py

@@ -186,17 +186,8 @@ def main():
     return 0
 
   parser = argparse.ArgumentParser(description='Download hermetic Xcode.')
-  parser.add_argument('--xcode-version', help='deprecated, do not use')
   args = parser.parse_args()
 
-  # Users in other repositories (v8, pdfium, webrtc) borrow Chromium's toolchain
-  # and depend on this script. Tolerate --xcode-version until all dependents are
-  # weaned.
-  if args.xcode_version is not None:
-    PrintError(
-        '%s: warning: --xcode-version is deprecated and will be removed' %
-        os.path.basename(__file__))
-
   if not PlatformMeetsHermeticXcodeRequirements():
     print('OS version does not support toolchain.')
     return 0