mdTooltip broken in Firefox since 0.9.8

[gpothier]

Tooltips do not appear in Firefox (v38). This problem occurs even in the Tooltip demo on the Angular Material page:

https://material.angularjs.org/latest/#/demo/material.components.tooltip

I don't think it is related to #3047, as I checked the pointer-events style in the button's hierarchy in the demo page, and nothing turned up.

[alirezamirian]

Actually it is related to #3047 and the issue will be resolved if you comment out the lines 132 and 134 which calls setVisible(true) only if pointer-events is 'none'