Problem with arrows when control by arrows

[rustho]

Description

The 'paper-tab' don't hide arrow button when it's needed if i control this by keyboard

Expected outcome

when I switched some elements by keyboard, on left side and right side to appear arrows.

Actual outcome

But state of arrow icon not changed. Arrows don't hide and don't appear.

Live Demo

Steps to reproduce

1. Put a paper-tabs element in the page.
2. Open the page in a web browser.
3. Click the paper-tabs element.
4. switch tabs by keyboard arrows to right.

Browsers Affected

• Chrome
• Firefox
• Safari 9
• Safari 8
• Safari 7
• Edge
• IE 11
• IE 10