[css-grid] Positioned items can be placed on the implicit grid

[css-grid] Positioned items can be placed on the implicit grid

The old code wrongly assumed that positioned items couldn't be placed
on the implicit grid.
However, the spec doesn't mention anything about this.

The patch fixes this issue, so now positioned items can be actually
placed on the implicit tracks.
Updated the test to follow the expected behavior.

BUG=615630
TEST=fast/css-grid-layout/grid-positioned-items-within-grid-implicit-track.html

Committed: https://crrev.com/5583f72362240b14f4f29facb90a24cd6a1ef516
Cr-Commit-Position: refs/heads/master@{#396711}

[Manuel Rego, 2016-05-28 14:52:01]

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

[svillar, 2016-05-30 07:29:54]

lgtm

[svillar, 2016-05-30 07:29:57]

lgtm

[Manuel Rego, 2016-05-30 07:41:55]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2016-05-30 07:42:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2021683002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2021683002/1

[commit-bot: I haz the power, 2016-05-30 09:39:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-05-30 09:39:02]

Try jobs failed on following builders:
  linux_android_rel_ng on tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[Manuel Rego, 2016-05-30 09:53:37]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2016-05-30 09:53:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2021683002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2021683002/1

[commit-bot: I haz the power, 2016-05-30 11:29:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-30 11:31:43]

Description was changed from

==========
[css-grid] Positioned items can be placed on the implicit grid

The old code wrongly assumed that positioned items couldn't be placed
on the implicit grid.
However, the spec doesn't mention anything about this.

The patch fixes this issue, so now positioned items can be actually
placed on the implicit tracks.
Updated the test to follow the expected behavior.

BUG=615630
TEST=fast/css-grid-layout/grid-positioned-items-within-grid-implicit-track.html
==========

to

==========
[css-grid] Positioned items can be placed on the implicit grid

The old code wrongly assumed that positioned items couldn't be placed
on the implicit grid.
However, the spec doesn't mention anything about this.

The patch fixes this issue, so now positioned items can be actually
placed on the implicit tracks.
Updated the test to follow the expected behavior.

BUG=615630
TEST=fast/css-grid-layout/grid-positioned-items-within-grid-implicit-track.html

Committed: https://crrev.com/5583f72362240b14f4f29facb90a24cd6a1ef516
Cr-Commit-Position: refs/heads/master@{#396711}
==========

[commit-bot: I haz the power, 2016-05-30 11:31:44]

Patchset 1 (id:??) landed as
https://crrev.com/5583f72362240b14f4f29facb90a24cd6a1ef516
Cr-Commit-Position: refs/heads/master@{#396711}