This complex machinery made sense for Blink, which has hundreds of
developers. In our case, we're just moving around two bools. We can do
that in a much simpler way.
Previously layout was exiting early because the frame view
was null. Now we actually compute some layout and paint the
text. This patch makes paragraph_builder_test pass.
This patch start down the road of implementing text layout and painting without
the DOM. We can construct a basic paragraph consisting of a single run of text
and we can get through layout without crashing.
