ios-simulator-full-configs which runs Earlgrey tests on main waterfall now takes around 1 hour to run.  That is bit too long for landing a CL.  To add this bot on CQ for iOS change only, we'll still need to shard ios_chrome_ui_egtests better first.  It is a huge chunk of tests which take 40 mins to run.  Also need more build slaves for its tryserver master.

Is there a reason we're not running that in more shards? I.e., is it a matter of getting more capacity, or something else?

(I've forgotten if we used to run more in parallel and had to ratchet back).

It was due to history reason that we followed KIF test's sharding mechanism.  We're currently working on more shards.  Add the tests for iOS changes is the short-term way to reduce tree breakages for iOS developers.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a7e41d218ced21bdd150d33708c63b61f4ee02a5

commit a7e41d218ced21bdd150d33708c63b61f4ee02a5
Author: Menglu Huang <huangml@chromium.org>
Date: Thu Nov 09 18:30:12 2017

Add EarlGrey tests tryjobs to all ios changes

Add EarlGrey tests tryjobs to ios changes.  We want to have EG
tests running for at least ios changes to reduce tree breakages.

Since the ios-simulator-full-configs has only 8 builders, iOS CLs might
experience extra landing time due to the tryjob size and limited capacity.

Bug:  782735 
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I8c00dbe1963893af19c37d7410e6d57c8d37ab5d
Reviewed-on: https://chromium-review.googlesource.com/759166
Reviewed-by: Rohit Rao (ping after 24h) <rohitrao@chromium.org>
Commit-Queue: Menglu Huang <huangml@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515214}
[modify] https://crrev.com/a7e41d218ced21bdd150d33708c63b61f4ee02a5/ios/PRESUBMIT.py