Tab Center bookmark position indicator bug

[pdehaan]

Filed by @karashata in https://github.com/mozilla/testpilot/issues/763

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I encountered a bug where the indicator for where a bookmark will be placed when moving bookmarks around in the toolbar is displayed significantly below the toolbar in the web page space when using Tab Center.

[kkot]

It is not nice but at least a bookmark is added to the right position but I hope it will be fixed.

[nickvergessen]

Just was about to report the same.

[ericawright]

@nickvergessen this one is a tough one to figure out, I tried ;)