Only block container children support pagination struts.

Removed partial support for pagination struts on table captions, since it
didn't work too well (caused inconsistent layout and also overlap with the
table section that followed). Instead, set a strut on the content inside the
caption (first line, for instance), just like we already do for table cells.

We had a check to avoid setting pagination struts on table cells, but there was
no similar check for table captions. Replaced the check with examining the
containing block. We may only set a pagination strut on a block if its
containing block is a block container (LayoutBlockFlow). This automatically
fixes similar issues with flexboxes and possible other layout modes too.


Review URL:

git-svn-id: svn:// bbb929c8-8fbe-4397-9dbb-9b2b20218538
8 files changed