Polymer/paper-button — pull request #43 by WrinklyNinja (2014-12-31 19:50:09+00:00)
Title: Fix IE flex-basis rounding error.

IE 11 seems to round the 0.000000001px flex-basis value down to 0px, which causes content to overflow buttons, rather than the buttons fitting the content. Using a value of auto instead fixes this.