Feature request: Support native selection mode in Chromium

[cary-rowen]

Is your feature request related to a problem? Please describe.

We've supported Firefox native selection mode in #15830.

This allows NVDA to operate the browser's selection functionality within its own virtual document.

cc @michaelDCurran pointed out in the original implementation:

Chromium implemented IAccessibleTextSelectionContainer, however much of the time its offset calculation seems to be wrong, thus the wrong native selection is made, thus this cannot be supported in Chromium at this point in time.

But now things have changed, as Chromium engineer cc @aleventhal stated in this comment

I believe the Chromium bugs with IAccessibleTextSelectionContainer are fixed in the latest Canary, so NVDA could try turning on support again. Let us know if there are new bugs that you see!

Describe the solution you'd like

Implement native selection mode in Chromium.

Describe alternatives you've considered

None

Additional context

Not yet

[Emil-18]

I think JAWS has had this functionality a very long time