The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2bd13b06dfd2fe72965e80597a58294ba12f811b

commit 2bd13b06dfd2fe72965e80597a58294ba12f811b
Author: Eugene But <eugenebut@chromium.org>
Date: Mon Oct 22 16:17:10 2018

Remove kWebErrorPages flag.

Notable changes:
  - removed redundant tests from ErrorPageTestCase
    (error_page_inttest cover these cases)
  - removed ErrorPageGenerator class
  - removed ErrorPageContent class
  - removed code which shows alert for non-printable
    pages

Bug:  725241 ,  694662 ,  840489 ,  859910 
Change-Id: I0cad718200a3682633c0babf9b57b45cff39a579
Reviewed-on: https://chromium-review.googlesource.com/c/1289995
Reviewed-by: Danyao Wang <danyao@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601604}
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/app/strings/ios_strings.grd
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/about_flags.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/ios_chrome_flag_descriptions.cc
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/ios_chrome_flag_descriptions.h
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/prerender/preload_controller.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/ui/activity_services/activity_service_controller_egtest.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/ui/browser_view_controller.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/ui/browser_view_controller_unittest.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/web/BUILD.gn
[delete] https://crrev.com/4676d794a8801cd5ae31b745ee124431d174f688/ios/chrome/browser/web/error_page_content.h
[delete] https://crrev.com/4676d794a8801cd5ae31b745ee124431d174f688/ios/chrome/browser/web/error_page_content.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/chrome/browser/web/error_page_egtest.mm
[delete] https://crrev.com/4676d794a8801cd5ae31b745ee124431d174f688/ios/chrome/browser/web/error_page_generator.h
[delete] https://crrev.com/4676d794a8801cd5ae31b745ee124431d174f688/ios/chrome/browser/web/error_page_generator.mm
[delete] https://crrev.com/4676d794a8801cd5ae31b745ee124431d174f688/ios/chrome/browser/web/error_page_generator_unittest.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/features.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/navigation/error_retry_state_machine.h
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/navigation/error_retry_state_machine.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/navigation/error_retry_state_machine_unittest.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/public/features.h
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/public/test/fakes/test_native_content_provider.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/public/web_state/ui/crw_native_content_provider.h
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/web_state/error_page_inttest.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/web_state/ui/crw_web_controller.mm
[modify] https://crrev.com/2bd13b06dfd2fe72965e80597a58294ba12f811b/ios/web/web_state/web_state_observer_inttest.mm