[css-grid] Percentage columns should remove scrollbar's width

[css-grid] Percentage columns should remove scrollbar's width

Currently the calculation of percentage columns
was not subtracting the scrollbar's size.
Fixed LayoutGrid::computeUsedBreadthOfSpecifiedLength()
to avoid this problem.

Added test to check the behavior for both columns and rows.

BUG=530504
TEST=fast/css-grid-layout/grid-percent-track-scrollbar.html

Committed: https://crrev.com/b4005a55e98d2d37e52da4cfc8d7d71a1f4950ad
git-svn-id: svn://svn.chromium.org/blink/trunk@202194 bbb929c8-8fbe-4397-9dbb-9b2b20218538

[Manuel Rego, 2015-09-11 11:51:03]

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

[svillar, 2015-09-11 13:25:01]

Makes total sense lgtm

[Manuel Rego, 2015-09-11 20:26:18]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2015-09-11 20:26:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338703002/1

[commit-bot: I haz the power, 2015-09-11 21:42:02]

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

[commit-bot: I haz the power, 2015-09-11 21:42:02]

Try jobs failed on following builders:
  cast_shell_linux on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linu...)

[cbiesinger, 2015-09-11 22:13:39]

lgtm

[Manuel Rego, 2015-09-14 07:15:01]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2015-09-14 07:15:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338703002/1

[commit-bot: I haz the power, 2015-09-14 08:27:09]

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

[commit-bot: I haz the power, 2015-09-14 08:27:10]

Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[Manuel Rego, 2015-09-14 08:37:01]

The CQ bit was checked by rego@igalia.com

[commit-bot: I haz the power, 2015-09-14 08:37:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338703002/1

[commit-bot: I haz the power, 2015-09-14 09:46:39]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=202194

[commit-bot: I haz the power, 2015-09-23 12:31:18]

Patchset 1 (id:??) landed as
https://crrev.com/b4005a55e98d2d37e52da4cfc8d7d71a1f4950ad