Compile Warning when building with ClojureScript 1.10.896

Compile Warning   target/public/cljs-out/webapp/devtools/async.cljs   line:13  column:14
```
  Use of undeclared Var goog.labs.userAgent.browser/isChrome

  12  (defn ^:dynamic needed? []
  13    (not (and (ua/isChrome) (ua/isVersionOrHigher fixed-chrome-version-for-async))))
                   ^---
```

Might be a ClojureScript bug? It can be avoided by `:refer [isChrome]` instead.