Currently, the items in the toolbar are above the middle of the address bar. More specifically, they are 1px below the top of the address bar. So, they are neither aligned to the middle nor the top.
It isn't very noticeable in normal usage, however, it is more pronounced when switching to compact mode, and using small size icons.
In the following screenshot, the green line is aligned with the top and bottom of the address bar:
This is how it appears in compact mode with small size icons: