Master internal.client.webrtc adds 2 slaves
'iOS64 Perf' and
'iOS64 Release',
and master internal.tryserver.webrtc changes its slaves to be
'ios_arm64_dbg' and
'ios_arm64_rel'
Added configs in mb_config.pyl for the new slaves.
Bug: chromium:785924
No-Try: true
Change-Id: I1e9bec918f6517bf0ff157ebcbe90e2f56ee1261
Reviewed-on: https://webrtc-review.googlesource.com/23843
Commit-Queue: Edward Lemur <ehmaldonado@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20724}