Changing out-of-flow-ness on a multicol child may affect the need for column sets.

Changing out-of-flow-ness on a multicol child may affect the need for column sets.

If a sole out-of-flow child becomes in-flow, we have to insert a column set,
since we suddenly have column content.

Conversely, if a sole in-flow child becomes out-of-flow, we have to remove the
column set, since there's no column content anymore.

BUG=486993
R=dsinclair@chromium.org,jchaffraix@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195693

[dsinclair, 2015-05-21 13:46:47]

The CQ bit was checked by dsinclair@chromium.org

[dsinclair, 2015-05-21 13:46:48]

lgtm

[commit-bot: I haz the power, 2015-05-21 13:47:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1148173003/1

[commit-bot: I haz the power, 2015-05-21 15:25:17]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=195693