mdBottomSheet: TypeError: Cannot read property 'runner' of undefined

[topherfangio]

There is an issue on the docs site which can throw the above error and break the site's formatting.

Steps to reproduce:

1. Open the bottom sheet demo
2. Click the "Show as Grid" button
3. Click the "Twitter" icon/button
4. VERY QUICKLY click another demo on the left before the toast starts to disappears

The error will be thrown and there will be two <md-content> tags on the page, the bottom one will be empty and cause 50% of the page to be empty (due to PR #4372).

[ThomasBurleson]

@matsko - how do we cancel an animation runner in $destory() ? Actually I think this may be a bug in ngAnimate... ?

[devversion]

This will be easy to fix after we have #6684 (this will also fix the toast overlaps; and will fix multiple interim elements running at same time), because then the interim elements won't get removed directly if hiding. They will be removed from stack, after their animation is done.

Then we can use $mdBottomsheet.destroy() and it will find an interim element (see here).