[New Multicolumn] Add RenderMultiColumnFlowThread::findSetRendering().
This is a preparatory patch for proper handling of dynamic insertion and
removal of elements inside multicol containers.
This new method will be needed when dynamically inserting spanners into the
middle of column content, since we will then need to split a column set in two
(and we need to figure out exactly which set to split). All of that will be
dealt with in a separate CL. For now, only call this method from some unit
tests, so see that it works.
BUG=347325
R=jchaffraix@chromium.org
Review URL: https://codereview.chromium.org/856383002
git-svn-id: svn://svn.chromium.org/blink/trunk@188810 bbb929c8-8fbe-4397-9dbb-9b2b20218538
3 files changed
