This part runs on both browser and node.

I spent a lot of time to find a pretty way to ignore mocha logs message (I don't wanna to use this invasive code).

I think if we prefix for coverage logs and add a filter need to modify the MochaReporter console.log at https://github.com/mozilla-b2g/js-test-agent/blob/master/lib/test-agent/mocha/json-stream-reporter.js#L31-L73
Because console.log has beed overwrite in here , but I think add blanket coverage flags in MochaReporter is little weird. Or do you have any good idea to do this?