[css-grid] Refactor code to manage positioned items

[css-grid] Refactor code to manage positioned items

Refactoring of LayoutGrid::offsetAndBreadthForPositionedChild()
that became really complex after adding RTL support for positioned items.

No new tests, no change of behavior.

BUG=273898
Committed: https://crrev.com/60077d7e66ae6b7b37202065560f28811fc64b56
Cr-Commit-Position: refs/heads/master@{#391495}

[Manuel Rego, 2016-05-04 08:20:51]

rego@igalia.com changed reviewers:
+ cbiesinger@chromium.org, jfernandez@igalia.com, svillar@igalia.com

[svillar, 2016-05-04 10:33:11]

lgtm

[Manuel Rego, 2016-05-04 10:44:01]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2016-05-04 10:44:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1945203002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1945203002/1

[commit-bot: I haz the power, 2016-05-04 13:41:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-04 13:43:06]

Description was changed from

==========
[css-grid] Refactor code to manage positioned items

Refactoring of LayoutGrid::offsetAndBreadthForPositionedChild()
that became really complex after adding RTL support for positioned items.

No new tests, no change of behavior.

BUG=273898
==========

to

==========
[css-grid] Refactor code to manage positioned items

Refactoring of LayoutGrid::offsetAndBreadthForPositionedChild()
that became really complex after adding RTL support for positioned items.

No new tests, no change of behavior.

BUG=273898

Committed: https://crrev.com/60077d7e66ae6b7b37202065560f28811fc64b56
Cr-Commit-Position: refs/heads/master@{#391495}
==========

[commit-bot: I haz the power, 2016-05-04 13:43:07]

Patchset 1 (id:??) landed as
https://crrev.com/60077d7e66ae6b7b37202065560f28811fc64b56
Cr-Commit-Position: refs/heads/master@{#391495}

[cbiesinger, 2016-05-04 22:32:37]

lgtm