run Test-iOS-... bots with --threads 0.
Yet another attempt to get the iOS bots stable.
As GPU testers, the iOS bots are already mostly single threaded,
but farm a good chunk of work like image encoding out to threads.
This will take them all the way to really single threaded.
BUG=skia:6748
Change-Id: I222e3ca402eee9d191c8a413b29a65d19c13e88a
Reviewed-on: https://skia-review.googlesource.com/20687
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed
