I just ran a Sunspider benchmark for an iPhone 5 with iOS 7 and the results are below for both Safari and Chrome.
As you can see, Safari on iOS 7 is about 5X faster than chrome for javascript, but this is mostly due to the fact that Apple cripples Chrome by forcing it to use a webview.
By Brian Roizen
“As you can Safari on iOS 7 is”
*As you can see 🙂
Fascinating benchmarks, feel bad for Chrome not being able to utilize the full capabilities of the device like Safari can.