Just as an FYI. 

As we can see on the following screenshot, once a site is Bookmarked the ToastBar covers the whole bottom toolbar. There's no way to dismiss it manually, because of that the App functionality is pretty limited until the ToastBar is automatically dismissed. 

https://drive.google.com/open?id=1hegT0549XphJhDQsJLKj58aVoxJHEg_W

rohitrao suggested using +setBottomOffset: when there is a bottom toolbar.
Looking at the MDCCatalog demo app, it is indeed possible to use setBottomOffset to shift the Snackbar up to avoid the bottom toolbar when there is one.

Currently, the snackbar shows up to confirm saving a page as bookmark, but it's placement obscures the bottom toolbar until the snackbar auto-dismisses.

noyau & I discussed this. The snackbar can be offset up so it does not obscures the bottom toolbar, but then the snackbar now appears as if it is part of the web content. That's a tradeoff because a user may confuse it with web site content.

At a minimum, I think this crbug should be re-labeled with Q4 since we won't work on this now. We may also consider this to be Fixed since we are showing a snackbar as confirmation.

Marking this available, Q4 and changing title.
I think this is part of the larger question "What do we want to do with snackbar".

My vote is to mark this as fixed and create a new bug (doesn't one already exist?) about what to do about snakbar placement in general. 

Note that it "being confused with content" is already the current behavior since we have no bottom toolbar, so there is nothing new introduced here.