But the Chrome/V8 teams is still benefiting from the existence of asm.js, because the subset of JS that people can use and expect good performance from is now well-defined. Prior to asm.js this kind of certainty wasn't available for either JS engine developers or JS authors.
I'm not sure I understand the purpose of your comment. Google's optimizations can achieve asmjs-like performance outside the well-defined subset so it doesn't necessarily benefit Google. If compile-to-js language authors target the subset ubiquitously and exclusively it may actually hurt Google.
