GitLab

* ci.star - ios13-beta-sim to run Chromium recipe
* mb_config.pyl - GN arguments for ios13-beta-sim
* testing/*.pyl, *.json - tests to bind to ios13-beta-sim
  * Replaced contents of ios-sim-cr-recipe with this as it is no
    longer needed. All introduced content (mixins, waterfall,
    test_suites) need a mapping, so I've replaced it as part of
    clean up as well.
* gn_isolate_map.pyl - updating all iOS test targets to generated
  scripts. Remains backwards compatible to iOS as required files
  are still there for iOS recipe consumption.
* BUILD.gn files - adding shard values for test targets that
  utilize parallelization via test runner.

Bug: 1055164
Change-Id: Id36ffdecd2935cacdf4825c99f26d2f6b561200d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2085118Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Jeff Yoon <jeffyoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748770}