Is it possible to avoid forced reflow？

[Alecyrus]

Environment

• Browser: latest chrome
• Version of smooth-scrollbar: latest

Issue Summary

the call of getSize() function will cause forced reflow.

Current Behavior

[Alecyrus]

@idiotWu There is another way to get Size, please consider use getBoundingClientRec to obtain position and calculate the dimension of elements, which will definitely not lead to reflow.

[idiotWu]

getBoundingClientRect definitely forces layout/reflow too: https://gist.github.com/paulirish/5d52fb081b3570c81e3a