Currently getBaselineChild only looks at the type of alignment for a grid item when determining if it should use it for the grid's baseline. However, it should also be checking the alignment context in which the item is in. For example, a last baseline aligned grid item that spans multiple rows may participate in baseline alignment in the last track is spans into as opposed to the first track it gets placed in
<rdar://problem/115441833>
https://github.com/WebKit/WebKit/pull/17746