Reland "Support 'xcode parallelization' flag on the test blocks level."

This reverts commit c79a7556da9e8e45df3dc0a160d8dd304a2b25cf.

Reason for revert: discussed offline; should be fine on branches due to how run.py parses args_json.

Original change's description:
> Revert "Support 'xcode parallelization' flag on the test blocks level."
> 
> This reverts commit 0f143592b6e3c6db8e13280055065f7ea6b38f1f.
> 
> Reason for revert: xcode parallelization flag should only be present for M73+.
> 
> Original change's description:
> > Support 'xcode parallelization' flag on the test blocks level.
> > 
> > Bug:920300
> > Change-Id: I6a926e12788bff54811b3c034106516e31224a88
> > Recipe-Nontrivial-Roll: build_limited_scripts_slave
> > Reviewed-on: https://chromium-review.googlesource.com/c/1404137
> > Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
> > Reviewed-by: Sergey Berezin <sergeyberezin@chromium.org>
> 
> TBR=justincohen@chromium.org,sergeyberezin@chromium.org,lindsayw@chromium.org,monufriienko@chromium.org
> 
> Change-Id: Id6d0cce488714bda96df7b2aba662c97993f5780
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 920300
> Reviewed-on: https://chromium-review.googlesource.com/c/1407213
> Reviewed-by: John Budorick <jbudorick@chromium.org>
> Commit-Queue: John Budorick <jbudorick@chromium.org>

TBR=justincohen@chromium.org,sergeyberezin@chromium.org,lindsayw@chromium.org,jbudorick@chromium.org,monufriienko@chromium.org

Change-Id: I3f27ea8a3567613442f08d1fb296e22b6e13e6e2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 920300
Reviewed-on: https://chromium-review.googlesource.com/c/1407218
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
40 files changed
tree: 1239a764b568af49ccf4cae2d1584390c13c5576
  1. infra/
  2. masters/
  3. scripts/
  4. site_config/
  5. slave/
  6. tests/
  7. third_party/
  8. .gitattributes
  9. .gitignore
  10. .vpython
  11. codereview.settings
  12. DEPS
  13. environment.cfg.py
  14. LICENSE
  15. OWNERS
  16. PRESUBMIT.py
  17. README.md
  18. WATCHLISTS
README.md

build

Hi build contributor! If you do any change in scripts/master/ or touching any master's html/ directories, you must restart master.chromium.fyi first and ensure that it still works before restarting other masters.

Recipes

If you're here to make a change to ‘recipes’ (the code located in scripts/slave/recipes*), please take a look at the README for more information pertaining to recipes.