Most of the time when I saw people develop "for Chrome" (like experiments), it would use standard stuff, but it only so happens that other browsers don't implement them [properly], yet. Or maybe I'm just awfully pedantic, but whenever I make stuff I tend to make it as close to the standard as possible, and fall back to vendor-specific stuff only when necessary (and usually try to cover all the major browsers).

Also, aren't most the Chrome-specific things disabled unless the app runs as an extension to discourage this type of chrome-only behaviour? I can't test/verify now, since I'm on my phone. This excludes CSS prefixes, since those are rarely needed these days anyway.