Safari font-weight rendering bug on some elements

[sdierauf]

I was clicking around on elements.polymer-project.org in safari [Version 8.0.7 (10600.7.7)] and I noticed the font weight rendering issue on a few of the elements during animations

related: http://stackoverflow.com/questions/9733011/safari-changing-font-weights-when-unrelated-animations-are-running and https://meta.discourse.org/t/text-weight-changing-on-hover/20495/3 contains this gif of a very similar issue

The following elements show this bug:

• paper-behaviors: clicking on the Radio button with focus state
• paper-dialog-behavior: clicking outside of modal alert when active
• paper-ripple: hover animation on third row icons <--- most noticeable, hover over any of the icons in the third row on https://p-catalog-staging.firebaseapp.com/elements/paper-ripple?view=demo:demo/index.html in safari and watch all the font weights render weird

[notwaldorf]

@blasten Do you mind taking a look at this, please? Thanks! :cake:

[notwaldorf]

Is this still reproducible? Does it look like it's related to https://code.google.com/p/chromium/issues/detail?id=406529?

[sdierauf]

Yes, still reproducible in Safari 9.0.2