Scrollbars visible before animation finishes

[jklein24]

The fact that the scrollbars show up before the content looks a bit weird. See the constrained height demo on:

https://www.polymer-project.org/components/paper-dropdown-menu/demo.html

to see what I mean.

[Nevraeka]

What browser/device/os/version do you see this on? I am trying to reproduce this now but the demo seems fine with regards to this on Mac Yosemite Chrome latest (the happy path). Trying IE10 on win7 next.

[Nevraeka]

@jklein24 +1 on IE10 (surprise!) lol. I think we can resolve this by temporarily setting the overflow to hidden until the animation completes. I'll try to get a PR ASAP.

[Nevraeka]

Also - just a note - this demo is for a related element (paper-dropdown-menu)

[jklein24]

My repro is actually on Chrome (dev channel - 41.0.2243) Linux.