Browser detect simply fails on Chrome on iOS

[Matias Meno]

This is the code in src/browser.dart:

  BrowserVersion get version {
    if (_version == null) {
      var value = _versionMatchers.map((matcher) => matcher())
          // vvvv This is the offending line vvvv
          .firstWhere((match) => match != null)
          .group(1);
      _version = new BrowserVersion(value);
    }
    return _version;
  }

If no match is found, then this simply throws