[Mac] Set tooltip for the app menu button

[Mac] Set tooltip for the app menu button

A tooltip for the app menu button is currently not displayed, although it is
defined in Toolbar.xib. In viewDidLoad: of ToolbarController, we replace the
app menu button from the xib with an AppToolbarButton instance for the material
design, so we need to explicitly set a tooltip for it again.

BUG=716749
Review-Url: https://codereview.chromium.org/2851063003
Cr-Commit-Position: refs/heads/master@{#468366}
Committed: https://chromium.googlesource.com/chromium/src/+/d2bad93f4d4f3417ce867dcd5631983cb2e36534

[Sungmann Cho, 2017-04-29 14:20:40]

sungmann.cho@navercorp.com changed reviewers:
+ rsesek@chromium.org

[Sungmann Cho, 2017-04-29 14:20:40]

Please take a look. Thanks!

[Robert Sesek, 2017-05-01 17:44:23]

lgtm

[Sungmann Cho, 2017-05-01 18:20:46]

The CQ bit was checked by sungmann.cho@navercorp.com

[commit-bot: I haz the power, 2017-05-01 18:21:21]

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, 2017-05-01 18:41:19]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493662846111110, "parent_rev":
"da7a05ce675223919327ef0c24226bbe16842c7b", "commit_rev":
"d2bad93f4d4f3417ce867dcd5631983cb2e36534"}

[commit-bot: I haz the power, 2017-05-01 18:41:27]

Description was changed from

==========
[Mac] Set tooltip for the app menu button

A tooltip for the app menu button is currently not displayed, although it is
defined in Toolbar.xib. In viewDidLoad: of ToolbarController, we replace the
app menu button from the xib with an AppToolbarButton instance for the material
design, so we need to explicitly set a tooltip for it again.

BUG=716749
==========

to

==========
[Mac] Set tooltip for the app menu button

A tooltip for the app menu button is currently not displayed, although it is
defined in Toolbar.xib. In viewDidLoad: of ToolbarController, we replace the
app menu button from the xib with an AppToolbarButton instance for the material
design, so we need to explicitly set a tooltip for it again.

BUG=716749

Review-Url: https://codereview.chromium.org/2851063003
Cr-Commit-Position: refs/heads/master@{#468366}
Committed:
https://chromium.googlesource.com/chromium/src/+/d2bad93f4d4f3417ce867dcd5631...
==========

[commit-bot: I haz the power, 2017-05-01 18:41:30]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/d2bad93f4d4f3417ce867dcd5631...