This patch does three things:
- Factors out the code that determines whether a box will create a new
formatting context for its children (and which type of context)
- Uses that code to mark all formatting context roots in layout tree
dumps. This makes it much easier to follow along with layout since
you can now see exactly where control is transferred to a new
formatting context.
- Rebaselines all existing layout tests, since the output format has
changed slightly.
This would previously assert in InlineFormattingContext because we had
an outwardly inline box that wasn't inwardly flow.
Fix this by converting text-based input boxes to inline-blocks. This is
an ad-hoc solution, and there might be a much better way to solve it.
