Perf tool incorrectly reports wasted time

[jeffchan]

This is a bug that's difficult to describe - I'm noticing that the Perf tool is incorrectly reporting wasted time even though the DOM did change.

To reproduce:

1. Visit http://fiddle.jshell.net/tfKYJ/58/show/light/
2. Make sure you're focused on the page
3. Press K to start Perf recording
4. Click on gray area
5. Press K to stop Perf recording

Only up the Javascript Console, and you'll notice that "wasted time" was reported, even though no time should've been wasted.

If you continue to play around, you'll notice inconsistencies. You may have to click several times during recording to get "wasted" time.

(original fiddle http://jsfiddle.net/tfKYJ/58/)

[sophiebits]

Perhaps a dupe of #1931.

[jeffchan]

Ah, looks like it may be very well a dupe. Sorry, should've checked!