From React.addons.Perf
Initially I thought I would use Perf by doing Perf.start (in componentWillUpdate) and Perf.stop + Perf.(printWasted|printInclusive|printExclusive) in (componentDidUpdate). But when I did that ReactDefaultPerf.js threw an error in measure.
So I looked into the code for Perf and found that stop funtion is:
stop: function() {
ReactPerf.enableMeasure = false;
},
it just sets the enableMeasure flag to false. While the initial start call injects the masure function and also resets the measurements.
After a few tests this is what I ended up with.