Fix tab is invisible when the next stop is close

Fix tab is invisible when the next stop is close

This patch fixes tab width to be at least the half of the space width,
so that it is always recognizable.

Before this patch, the minimum was 1/64px, which is too narrow to
recognize a tab is there. It also helps the stability for rounding
errors.

This patch also moves ShapeResult::createForTabulationCharacters() from
HarfBuzzShaper.cpp to ShapeResult.cpp.

BUG=635717
Committed: https://crrev.com/371ed3a69920683cccd0431ce9ce7c95ea324845
Cr-Commit-Position: refs/heads/master@{#417905}

[kojii, 2016-09-11 13:23:00]

The CQ bit was checked by kojii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-11 13:23:11]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-11 14:39:00]

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

[commit-bot: I haz the power, 2016-09-11 14:39:00]

Dry run: This issue passed the CQ dry run.

[kojii, 2016-09-11 14:50:53]

The CQ bit was checked by kojii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-11 14:51:00]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kojii, 2016-09-11 15:06:16]

The CQ bit was checked by kojii@chromium.org to run a CQ dry run

[kojii, 2016-09-11 15:06:22]

The CQ bit was unchecked by kojii@chromium.org

[kojii, 2016-09-11 15:06:36]

Patchset #2 (id:20001) has been deleted

[kojii, 2016-09-11 15:06:45]

The CQ bit was checked by kojii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-11 15:06:59]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-11 16:32:34]

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

[commit-bot: I haz the power, 2016-09-11 16:32:35]

Dry run: This issue passed the CQ dry run.

[kojii, 2016-09-12 05:18:05]

Description was changed from

==========
tab-size

BUG=
==========

to

==========
Fix tab is invisible when the next stop is close

This patch fixes tab width to be at least the half of the space width,
so that it is always recognizable.

Before this patch, the minimum was 1/64px, which is too narrow to
recognize a tab is there. It also helps the stability for rounding
errors.

This patch also moves ShapeResult::createForTabulationCharacters() from
HarfBuzzShaper.cpp to ShapeResult.cpp.

BUG=635717
==========

[kojii, 2016-09-12 06:35:00]

The CQ bit was checked by kojii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-12 06:35:07]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kojii, 2016-09-12 06:35:14]

Patchset #2 (id:40001) has been deleted

[kojii, 2016-09-12 09:39:23]

kojii@chromium.org changed reviewers:
+ eae@chromium.org

[kojii, 2016-09-12 09:39:24]

PTAL.

[eae, 2016-09-12 09:41:29]

LGTM

[kojii, 2016-09-12 10:09:08]

The CQ bit was unchecked by kojii@chromium.org

[kojii, 2016-09-12 10:09:15]

The CQ bit was checked by kojii@chromium.org

[commit-bot: I haz the power, 2016-09-12 10:09:27]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-12 10:13:42]

Committed patchset #2 (id:60001)

[commit-bot: I haz the power, 2016-09-12 10:15:34]

Description was changed from

==========
Fix tab is invisible when the next stop is close

This patch fixes tab width to be at least the half of the space width,
so that it is always recognizable.

Before this patch, the minimum was 1/64px, which is too narrow to
recognize a tab is there. It also helps the stability for rounding
errors.

This patch also moves ShapeResult::createForTabulationCharacters() from
HarfBuzzShaper.cpp to ShapeResult.cpp.

BUG=635717
==========

to

==========
Fix tab is invisible when the next stop is close

This patch fixes tab width to be at least the half of the space width,
so that it is always recognizable.

Before this patch, the minimum was 1/64px, which is too narrow to
recognize a tab is there. It also helps the stability for rounding
errors.

This patch also moves ShapeResult::createForTabulationCharacters() from
HarfBuzzShaper.cpp to ShapeResult.cpp.

BUG=635717

Committed: https://crrev.com/371ed3a69920683cccd0431ce9ce7c95ea324845
Cr-Commit-Position: refs/heads/master@{#417905}
==========

[commit-bot: I haz the power, 2016-09-12 10:15:35]

Patchset 2 (id:??) landed as
https://crrev.com/371ed3a69920683cccd0431ce9ce7c95ea324845
Cr-Commit-Position: refs/heads/master@{#417905}