Compatibility with Iron Icons (And other Iron Widgets) on legacy browsers

[jamesrboatwright]

I'm running into an issue with using Polymer CSS build with Iron Icon. It looks that CSS Build will remove duplicates of CSS properties that are inside a CSS Mixin. This causes problems when using Iron Icon, because it uses duplicate CSS properties as a fallback for legacy browsers.

So this

--layout-inline: { display: -ms-inline-flexbox; display: -webkit-inline-flex; display: inline-flex; };

Becomes

--layout-inline: { display: inline-flex; };

This is particularly a problem when you have to support legacy browsers and devices. Thank you