Prepare height calculation methods in LayoutFlowThread for nested multicol.

Prepare height calculation methods in LayoutFlowThread for nested multicol.

Rename pageLogicalHeight() in LayoutMultiColumnSet to
pageLogicalHeightForOffset(), so that it matches the naming of
pageRemainingLogicalHeightForOffset().

Move the innards to LayoutMultiColumnSet. And some 0 -> LayoutUnit() cleanup.

Had to adjust some call sites because of this and introduce
isPageLogicalHeightKnown().

No behavioral changes intended for now.

R=jchaffraix@chromium.org,leviw@chromium.org
BUG=447718
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200272

[leviw_travelin_and_unemployed, 2015-08-10 20:37:30]

The CQ bit was checked by leviw@chromium.org

[leviw_travelin_and_unemployed, 2015-08-10 20:37:31]

lgtm

Simple enough to review :)

[commit-bot: I haz the power, 2015-08-10 20:37:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1282353002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1282353002/1

[mstensho (USE GERRIT), 2015-08-10 20:44:17]

Whoa! It got reviewed even before I published it.

FWIW, no worries. It was ready for review. :) Thanks!

[leviw_travelin_and_unemployed, 2015-08-10 21:32:38]

On 2015/08/10 at 20:44:17, mstensho wrote:
> Whoa! It got reviewed even before I published it.
> 
> FWIW, no worries. It was ready for review. :) Thanks!

I CANNOT BE STOPPED!

[leviw_travelin_and_unemployed, 2015-08-10 21:33:08]

On 2015/08/10 at 21:32:38, leviw wrote:
> On 2015/08/10 at 20:44:17, mstensho wrote:
> > Whoa! It got reviewed even before I published it.
> > 
> > FWIW, no worries. It was ready for review. :) Thanks!
> 
> I CANNOT BE STOPPED!

#papayawhip

[commit-bot: I haz the power, 2015-08-10 22:50:53]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200272