Sana, do you know who maintains the presubmit script?  Chrome iOS doesn't include the chrome/ directory, so we want to add a check to prevent IS_IOS usage in that directory.

I'm not aware of anyone really maintaining it, it's more like anyone who wants to add or modify a check can do so themselves.

If you look at CheckForInvalidOSMacros in PRESUBMIT.py you should get some idea about how to add the desired check.

Then just send the CL to one of the OWNERS of PRESUBMIT.py.

BTW, r377377 originally removed all the iOS ifdefs. So r480991 is the amount that creeped back in, in the following 16 months.

4 more months, a few more creeps in. https://chromium-review.googlesource.com/762873

Eh, not that hard to augment CheckForInvalidOSMacros. Don't want to keep sending CLs to fix this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/29278b40c52ed90f3ab2eef0ed9623ead9f18778

commit 29278b40c52ed90f3ab2eef0ed9623ead9f18778
Author: Lei Zhang <thestig@chromium.org>
Date: Fri Nov 10 22:34:17 2017

Add a presubmit check to keep OS_IOS out of chrome/

BUG= 735628 

Change-Id: I2eb4b87c86fbbd06c73ed6d1602c030b35d90d2a
Reviewed-on: https://chromium-review.googlesource.com/762876
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515718}
[modify] https://crrev.com/29278b40c52ed90f3ab2eef0ed9623ead9f18778/chrome/PRESUBMIT.py
[add] https://crrev.com/29278b40c52ed90f3ab2eef0ed9623ead9f18778/chrome/PRESUBMIT_test.py