High CPU Usage on chrome/mac because of tooltips

[mani902]

As part of implementing jQuery UI Tooltip library for our case, we noticed a very significant increase in CPU usage on chrome on mac. Using the chrome profiling tools, we found out

// Handle tracking tooltips that are shown with a delay (#8644). As soon
		// as the tooltip is visible, position the tooltip using the most recent
		// event.
		if ( this.options.show && this.options.show.delay ) {
			delayedShow = setInterval(function() {
				if ( tooltip.is( ":visible" ) ) {
					position( positionOption.of );
					clearInterval( delayedShow );
				}
			}, $.fx.interval );
		}

piece of code is setting timers and it increased the CPU usage by 40-50 % on some machines. Looking at the original ticket, this was related to handle the tracking tooltips with delay option. However, there is no check for the track option before setting the timer, and we are not using track=true tooltips in our case, only delay. So unknowingly using delay is causing a huge amount of cpu usage.

First fix is to add the check for the track option also, so that unless someone is not using both track and delay option, timers should not be set. Second will be to identify why the cpu usage increases so much on mac/chrome combination.

[Mani Mishra]

Tooltip: Use show.delay update only when track option is active

Fixes #14682 Closes gh-1613

Changeset: d5732327078709c3680385c79a2106f263009f84