Generating Data:
$et = EventTracer("myeventlog.json");
$et->begin("Eating Cake");
[...]
$et->end();
If filename isn't specified, then data will be buffered
in-memory ($et->buffer) and can be written to disk in
one go with $et->flush($filename).
Viewing Data:
Visit chrome://tracing
Load JSON file
Format Spec:
Uses the JSON Array Format because that's the one which can be appended to from multiple threads