Improve views::Slider keyboard handling.

Improve views::Slider keyboard handling.

- more RTL-friendly
- handle up and down arrows

BUG=663767
Review-Url: https://codereview.chromium.org/2717583002
Cr-Commit-Position: refs/heads/master@{#453272}
Committed: https://chromium.googlesource.com/chromium/src/+/d2af662cd05d4c85b9d4936b4bb02ef67a952418

[Evan Stade, 2017-02-23 21:43:19]

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

[Evan Stade, 2017-02-23 21:43:32]

estade@chromium.org changed reviewers:
+ sadrul@chromium.org

[commit-bot: I haz the power, 2017-02-23 21:44:06]

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, 2017-02-23 22:49:39]

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

[commit-bot: I haz the power, 2017-02-23 22:49:40]

Dry run: This issue passed the CQ dry run.

[sadrul, 2017-02-25 01:33:54]

lgtm

Add a test-case like the existing SliderTest.SliderValueForKeyboard (especially
for rtl)?

[Evan Stade, 2017-02-27 17:45:23]

The CQ bit was checked by estade@chromium.org

[Evan Stade, 2017-02-27 17:45:23]

The patchset sent to the CQ was uploaded after l-g-t-m from sadrul@chromium.org
Link to the patchset: https://codereview.chromium.org/2717583002/#ps20001
(title: "add test coverage")

[commit-bot: I haz the power, 2017-02-27 17:45:51]

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

[Evan Stade, 2017-02-27 17:46:26]

thanks. test coverage added

[commit-bot: I haz the power, 2017-02-27 18:41:33]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1488217523340670,
"parent_rev": "61c0a31a9889b25af7c5d05edea59a59f04fdffa", "commit_rev":
"d2af662cd05d4c85b9d4936b4bb02ef67a952418"}

[commit-bot: I haz the power, 2017-02-27 18:42:17]

Description was changed from

==========
Improve views::Slider keyboard handling.

- more RTL-friendly
- handle up and down arrows

BUG=663767
==========

to

==========
Improve views::Slider keyboard handling.

- more RTL-friendly
- handle up and down arrows

BUG=663767

Review-Url: https://codereview.chromium.org/2717583002
Cr-Commit-Position: refs/heads/master@{#453272}
Committed:
https://chromium.googlesource.com/chromium/src/+/d2af662cd05d4c85b9d4936b4bb0...
==========

[commit-bot: I haz the power, 2017-02-27 18:42:17]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/d2af662cd05d4c85b9d4936b4bb0...