RenderGrid needs to pop its LayoutState before relayout.

RenderGrid needs to pop its LayoutState before relayout.

All other renderers do this, and so should RenderGrid. If the new
layout affects the presence of scrollbars (if overflow-[xy] is auto),
another layout pass may be required. Pushing two LayoutState objects
for the same object is unhealthy inside multicol, because the stack
in RenderFlowThread is implemented using a hash map, for some reason.

BUG=414456
R=chrishtr@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185577

[mstensho (USE GERRIT), 2014-11-18 23:08:41]

I find it hard to understand that RenderFlowThread uses a hash map to implement
a stack. I could fix that instead, but what I came up with here should be sane
as well, and simpler. :)

[chrishtr, 2014-11-18 23:43:24]

chrishtr@chromium.org changed reviewers:
+ leviw@chromium.org

[chrishtr, 2014-11-18 23:43:24]

Seems logical, but I'm not as expert in this code. Adding Levi.

[leviw_travelin_and_unemployed, 2014-11-19 00:11:25]

I'm not sure about the choice in RenderFlowThread... Sounds like you could fix
that, too.

LGTM.

[mstensho (USE GERRIT), 2014-11-19 07:46:41]

The CQ bit was checked by mstensho@opera.com

[commit-bot: I haz the power, 2014-11-19 07:46:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/739743002/1

[commit-bot: I haz the power, 2014-11-19 08:58:37]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=185577