The roll takes new feature to download Xcode & iOS runtimes separately.
The interface used by builder machines is untouched, but implementation
changed for new Xcode packages.

Recipe-Nontrivial-Roll: build
Recipe-Nontrivial-Roll: infra
Recipe-Nontrivial-Roll: build_limited_scripts_slave
Bug: 1191260
Change-Id: If0554e116bcb92c0b125693e1f555e52e22c10f4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2890331Reviewed-by: Jeff Yoon <jeffyoon@google.com>
Commit-Queue: Zhaoyang Li <zhaoyangli@chromium.org>