[Custom Tab]Adjust padding for "Powered by Chrome" prompt text

[Custom Tab]Adjust padding for "Powered by Chrome" prompt text

Modifying the padding of the last menu item view is hard, but adjust the
height of the prompt view is lighter and easier. This CL takes this
approach to make the padding for each menu more symmetric.

BUG=527537
R=yusufo@chromium.org

Committed: https://crrev.com/efe475ce3e0cd00f1edc0a905c40e8f7f8d90937
Cr-Commit-Position: refs/heads/master@{#347345}

[Ian Wen, 2015-09-03 05:54:09]

PTAL :)

[Ian Wen, 2015-09-03 18:04:03]

ianwen@chromium.org changed reviewers:
+ aurimas@chromium.org

[Ian Wen, 2015-09-03 18:04:04]

aurimas@chromium.org: Could you help me review the menu change? Thanks!

[aurimas (slooooooooow), 2015-09-03 20:08:06]

lgtm given than rolfe@ is ok with the white gap one the last menu item is
selected.

[Ian Wen, 2015-09-03 21:14:08]

The CQ bit was checked by ianwen@chromium.org

[commit-bot: I haz the power, 2015-09-03 21:14:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1323613004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1323613004/1

[Ian Wen, 2015-09-03 21:17:00]

The CQ bit was unchecked by ianwen@chromium.org

[Ian Wen, 2015-09-04 06:28:11]

The CQ bit was checked by ianwen@chromium.org

[commit-bot: I haz the power, 2015-09-04 06:28:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1323613004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1323613004/1

[commit-bot: I haz the power, 2015-09-04 06:33:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-04 06:34:22]

Patchset 1 (id:??) landed as
https://crrev.com/efe475ce3e0cd00f1edc0a905c40e8f7f8d90937
Cr-Commit-Position: refs/heads/master@{#347345}