The 'firebase-messaging' element causes an error on-message when combined with the 'share-menu' element

[fredmanders]

Description

I have the firebase-messaging element from polymerfire and the share-menu element in the same element in my app. When I receive a Firebase Cloud message in the foreground, the on-message event is fired. I think the widgets.js from Twitter also intercepts this event, resulting in an error.

Expected outcome

The firebase-messaging elements on-message event is handled without any errors.

Actual outcome

An error occurs:

Uncaught TypeError: Cannot read property 'twttr.button' of undefined at o (widgets.js:formatted:4740) at s._onMessage (widgets.js:formatted:4772) at widgets.js:formatted:694 at HTMLElement.fire (legacy-element-mixin.html:372) at firebase-messaging.html:114 at Array.forEach (<anonymous>) at Object.next (firebase-messaging.html:112) at firebase-app.js:3453 at firebase-app.js:3453 at <anonymous> o @ widgets.js:formatted:4740 _onMessage @ widgets.js:formatted:4772 (anonymous) @ widgets.js:formatted:694 fire @ legacy-element-mixin.html:372 (anonymous) @ firebase-messaging.html:114 (anonymous) @ firebase-messaging.html:112 (anonymous) @ firebase-app.js:3453 (anonymous) @ firebase-app.js:3453 Promise resolved (async) e.sendOne @ firebase-app.js:3453 e.forEachObserver @ firebase-app.js:3453 e.next @ firebase-app.js:3453 (anonymous) @ firebase-messaging.js:1618

Steps to reproduce

1. Put a firebase-messaging element in the page.
2. Put a share-menu element in the page.
3. Open the page in a web browser.
4. Receive a Firebase Cloud message with the page in the foreground.