GitLab

We need to set zero page logical height in LayoutState when column
height is unknown (when the columns haven't yet been
balanced). There's code that assumes that non-zero page height means
that page height is known. Lying about this makes the pagination code
believe that every top margin is adjacent to a column break, which
makes it eat and ignore all top margins.

This should be cleaned up, but it's easier to wait until the old
multicol code has been removed.

BUG=353587

Review URL: https://codereview.chromium.org/209863003

git-svn-id: svn://svn.chromium.org/blink/trunk@170335 bbb929c8-8fbe-4397-9dbb-9b2b20218538