mozilla/pdf.js — pull request #4564 by bobmyers (2014-04-05 12:19:35+00:00)
Title: Display print icon.

The `supportsPrinting` property was being set based on the presence of the `mozPrintCallback` property on the `canvas` element. Even though that is polyfilled on other browsers, this caused the print icon to not be displayed. Set it to `true` in all cases.