CSS has a line-height property with values like '1.3', but we also have
a measured pixel value for line height. It's important to keep these
separate conceptually.
This fork of React allows data-react-skip-selection-restoration to be
defined on input elements, skipping costly selection restoration that
occurs when the input element is focused during reconciliation.
Because lines are opaque and any area of a selection that overlaps a
line is actually rendered on the line itself, the screen-spanning
background of a multi-line selection can actually be rendered as a
single div spanning the entire screen from the first row to the
penultimate row of the selection.
This is getting closer, but lines still need to be opaque. Multi-line
selections will still need to be rendered behind the line layers so they
can extend to the edge of the viewport, so this code still has value.
