No, not exactly.

Chrome is using the web view without JIT compiling for JavaScript that Safari can take advantage of. That being said, it's not something that's surprising. It's a known issue.

No, apps using UIWebView don't get the "fast" JS engine, for security reasons. Only MobileSafari has that.

EDIT: Gah, beaten by a few seconds by jasonlotito.

From what I understand, Chrome (and any non-native app) doesn't have access to the JavaScript engine that Safari does. That's why the JavaScript benchmark results are so disparate between Safari and Chrome for iOS.