Problem:
Chrome for iOS implements WebUI by fetching main html document and its subresources from net stack, flattening html and force feeding it to WKWebView. This approach uses simple html parser, regexps and large strings concatenation all because iOS 10 and lower does not support custom url protocols for WKWebView. Current solution works fine, but the code is quite complex 

Solution:
Starting from ios 11 WKWebView supports custom URL protocols via WKURLSchemeHandler API. There are no visible user benefits in using new API, and because Chrome has to support iOS10, there is no reason to switch. WKURLSchemeHandler works just fine as demonstrated in https://chromium-review.googlesource.com/c/566091/ and we should switch to use new API after dropping iOS 10.

Design doc:
https://docs.google.com/document/d/1vZFxG8ml2yKanIEzMEEosXJDGKfJRUDwlkz5qKkR1w8/edit#

 Issue 740772  has been merged into this issue.

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Is this still blocking and needed?

We still need this refactoring.

The NextAction date has arrived: 2018-12-01