First off, thanks for maintaining Tachometer! It's a really awesome tool.

This is just a minor issue. Sometimes I like to use this pattern:

performance.mark('foo')
// do something
performance.measure('foo', 'foo')

Unfortunately, if I do this, then I can't use the following in my tachometer.json:

{
  "measurement": [
    {
      "mode": "performance",
      "entryName": "foo"
    }
  ]
}

The reason is that Tachometer doesn't know whether I'm talking about the foo mark or measure. So as soon as it sees the mark, it uses that, rather than waiting for the measure.

Something like this would be great:

{
  "measurement": [
    {
      "mode": "performance",
      "entryName": "foo",
      "entryType": "measure"
    }
  ]
}

In the meantime, the workaround is to use a different name for the mark and the measure.