The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8dc3974189d1043c594c7ddf120ba907019e0ae7

commit 8dc3974189d1043c594c7ddf120ba907019e0ae7
Author: Mike Dougherty <michaeldo@chromium.org>
Date: Fri Nov 10 01:40:52 2017

Add timeout to Captive Portal detection on iOS.

Captive portal detection may take a very long time in which case the SSL
error interstitial will be shown to the user instead of waiting to
determine the captive portal state.

Bug:  754378 
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I31c982f581d4b1cb8b86dfb39c722955f6769cd6
Reviewed-on: https://chromium-review.googlesource.com/759169
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515406}
[modify] https://crrev.com/8dc3974189d1043c594c7ddf120ba907019e0ae7/ios/chrome/browser/ssl/BUILD.gn
[modify] https://crrev.com/8dc3974189d1043c594c7ddf120ba907019e0ae7/ios/chrome/browser/ssl/ios_ssl_error_handler.h
[modify] https://crrev.com/8dc3974189d1043c594c7ddf120ba907019e0ae7/ios/chrome/browser/ssl/ios_ssl_error_handler.mm
[modify] https://crrev.com/8dc3974189d1043c594c7ddf120ba907019e0ae7/ios/chrome/browser/ssl/ios_ssl_error_handler_unittest.mm