Lighthouse optimization : Does not use passive listeners to improve scrolling performance

[juliender]

Describe the bug
In lighthouse, there is a warning concerning event listeners :

Does not use passive listeners to improve scrolling performance
Consider marking your touch and wheel event listeners as passive to improve your page's scroll performance.

Code
Lines 202-207
this.$refs.track.addEventListener('touchstart', this.handleMouseDown)

The warning disappears by adding {passive : true}

Ie for line 202, the code becomes this.$refs.track.addEventListener('touchstart', this.handleMouseDown, {passive : true})

Regards