Remove LayoutFlowThread stuff from line layout code.
We used to force full line layout if we had a flow thread with no column sets.
This may have made sense at some point in the past, where we created column
sets on the fly during layout, but we don't do that anymore (because we don't
mutate the layout tree structure during layout anymore). If we have no column
sets, it means that we cannot have any lines, since there's no column content
(because if there were, we'd have at least one column set). So it was a
pointless (albeit harmless) check.
There was also a flow thread check around some code that checks if previously
created lines will be affected by floats in new ways. If this is the right
thing to do for flowthread based fragmentation, it's also the right thing to do
for non-flowthread based (e.g. printing) fragmentation, so just remove the
check.
Also reordered and cleaned up checkPaginationAndFloatsAtEndLine() somewhat. We
don't have to do anything at all unless we have floats. Let's figure this out
as early as possible and bail if we can.
Also locate the last line in the block flow in a simpler way. Call
lastRootBox() instead of walking some chain of lines all the way to the end.
Review URL: https://codereview.chromium.org/1915803004
Cr-Commit-Position: refs/heads/master@{#389720}
2 files changed
