The instructions at [1] are a little onerous:

1. Open the Settings app
2. Scroll to Chrome Beta/Dev/Canary and press
3. Scroll down to Experimental Settings and press
4. Scroll to EXTRA FLAGS (ONE PER LINE)
5. Toggle "Append Extra Flags" to ON
6. Set Flag1 to "--mark-non-secure-as=show-non-secure-passwords-cc-ui" (without the quotes)

It would be nice to add --mark-non-secure-as to chrome://flags on iOS for all our testers, and for devs who care about iOS web.

about_flags.mm on iOS [2] looks pretty straightforward.
However, the existing definition of kMarkHttpAsChoices [3] is in `chrome/browser/about_flags.cc`, and the flag UI description strings are in the general Chrome strings file (generated_resources).

A simple hammer to this problem would be to duplicate all the strings in iOS, but that's not great.

emilyschechter@: What is the right priority for this? I'm okay with dropping it, given that there is already a (cumbersome) way to set the flag for (non-stable) builds. However, I think we will get enough benefit in the long term from implementing this.

eugenebut@, what's the best way to expose a feature entry on iOS as well as other platforms?
estark@, if it turns out to help, do you see any problems with moving the all the strings to the security_state component, and exposing kMarkHttpAsChoices in the switches file?

[1] https://codereview.chromium.org/2466143002
[2] https://cs.chromium.org/chromium/src/ios/chrome/browser/about_flags.mm
[3] https://cs.chromium.org/chromium/src/chrome/browser/about_flags.cc?q=kMarkHttpAsChoices&sq=package:chromium&l=205&dr=CSs
[4] https://cs.chromium.org/chromium/src/chrome/browser/about_flags.cc?dr=C&q=%7B%22mark-non-secure-as%22,&sq=package:chromium&l=1468