Paper-tooltip does not work when used with Angular2 in Firefox

[orendin]

Description

When using in combination with Angular2 in Shadow dom mode, the paper-tooltip does not work properly. Occasionally, the very first time the page is loaded, it works (e.g. is hidden initially and shows up on hover). However, every subsequent load seems to be broken (e.g. text of tooltip shows overflowing other text). This works in Chrome latest, but not in Firefox.
This issue is also mentioned in my stackoverflow topic:
https://stackoverflow.com/questions/40802603/angular2-with-polymer-elements-cross-browser-support#
Not sure if I have to talk to you guys or with the angular team to figure out where the problem is and how to fix it.

Expected outcome

The tooltip (text) is expected to be hidden initially and to always work the same way, showing up on hover. This works in Chrome, but not in Firefox (and neither in IE for that matter). The element is marked as working in firefox latest version.

Actual outcome

The tooltip (text) is showing up on initial page load, overflowing other elements on the page.

Live Demo

http://plnkr.co/edit/u9hLaEDxsEInRD4KKmmz?p=preview

Steps to reproduce

1. Put together a very basic Angular2 app (see my plunkr)
2. Set the window.Polymer to shadow dom (see my plunkr)
3. Add paper-tooltip
4. Look at the page in Firefox / IE
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Browsers Affected

• Chrome
• Firefox
• Safari 9
• Safari 8
• Safari 7
• Edge
• IE 11
• [?] IE 10