allow disabling PaperInkyFocusBehavior?

[jab]

We're seeing unwanted keyboard focus-related styles on our paper-icon-buttons, in particular on mobile, where we're specifically only building for the no-keyboard use case. I’ve tracked this down to PaperInkyFocusBehavior, which is unconditionally added to paper-icon-button's behaviors. Would it be possible to allow paper-icon-button users to opt out of PaperInkyFocusBehavior?

(In the meantime, we can work around this by pegging to a fork of paper-behaviors with a modified _focusChanged method. As a bonus, it also works around this issue, which we're also hitting: PolymerElements/paper-menu-button#101)

Thanks for your consideration and for all the great work!

[jab]

(To be clear, we still want the ripple when the button is tapped, we just don’t want the button to get any different styles when it has focus.)

[notwaldorf]

This is bad for a11y, and it's not a thing we'd like to give the option to accidentally turn off :(

[jab]

Thanks for taking a look @notwaldorf! After digging a little deeper, I think this is actually a bug in paper-behaviors. Just opened PolymerElements/paper-behaviors#80, and will close this now since it seems like discussion should move there.