Multi-browser report displayed as combined results

When I was used the combined result by code below, I was getting best result instead of combination of all.

```
coverageReporter : {
type : 'html',
dir : 'reports/html/'
}
```

I found istanbul-combine in npm which doing it, but there I have no idea how to call it as post-process script in Phpstorm.

Is there possibility to combine all lines from different browsers? Or is it possible to implement it?

Start by reviewing the coverageReporter configuration shown in the issue and how this Karma plugin produces HTML reports. Compare the requested multi-browser combination with the behavior of istanbul-combine. The issue names no repository files, tests, or concrete acceptance criteria, so the expected combined report still needs to be defined.

Written by the indexing model from the issue text.