[webkit-dev] CSS Logical Properties and Values

[Oriol Brufau]

I have written a patch for adding logical shorthand properties. However,
I'm not much sure about how I can implement them behind a flag.

I tried hiding them behind a run-time flag. But unlike Blink, it seems I
can't do this easily in CSSProperties.json.
Instead, I wrapped the code added in CSSPropertyParser.cpp and
CSSComputedStyleDeclaration.cpp inside conditionals with
`RuntimeEnabledFeatures::sharedFeatures().cssLogicalEnabled()`.
This disables the effects of the properties, but doesn't prevent them
from being exposed via `prop in element.style`.

So I will try a compile flag instead. But there are some Web Platform
Tests for the new properties, and I would like them to pass.
Is there a way to tell the testbot to compile with this flag?

I would appreciate some guidance on the preferred way of doing this.