Fix the settings button and UMA metrics for the message center

Fix the settings button and UMA metrics for the message center

The settings button was unintentionally broken for Windows and
Linux users in 2799653004, as was gathering of some UMA. This
CL offers a slight refactoring that meets all goals.

BUG=706658
Review-Url: https://codereview.chromium.org/2807623002
Cr-Commit-Position: refs/heads/master@{#463339}
(cherry picked from commit 9b6e3c78898f12a0183edffb62d189cb716c6135)

Review-Url: https://codereview.chromium.org/2818063002 .
Cr-Commit-Position: refs/branch-heads/3029@{#707}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/ebce3bd778c9770581cb11f2c90219fac48728f4

[yhanada, 2017-04-14 04:33:24]

Description was changed from

==========
Fix the settings button and UMA metrics for the message center

The settings button was unintentionally broken for Windows and
Linux users in 2799653004, as was gathering of some UMA. This
CL offers a slight refactoring that meets all goals.

BUG=706658

Review-Url: https://codereview.chromium.org/2807623002
Cr-Commit-Position: refs/heads/master@{#463339}
(cherry picked from commit 9b6e3c78898f12a0183edffb62d189cb716c6135)
==========

to

==========
Fix the settings button and UMA metrics for the message center

The settings button was unintentionally broken for Windows and
Linux users in 2799653004, as was gathering of some UMA. This
CL offers a slight refactoring that meets all goals.

BUG=706658

Review-Url: https://codereview.chromium.org/2807623002
Cr-Commit-Position: refs/heads/master@{#463339}
(cherry picked from commit 9b6e3c78898f12a0183edffb62d189cb716c6135)

Review-Url: https://codereview.chromium.org/2818063002 .
Cr-Commit-Position: refs/branch-heads/3029@{#707}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/ebce3bd778c9770581cb11f2c902...
==========

[yhanada, 2017-04-14 04:33:27]

Committed patchset #1 (id:1) manually as
ebce3bd778c9770581cb11f2c90219fac48728f4.

[alexmos, 2017-04-14 20:52:07]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2823673002/ by alexmos@chromium.org.

The reason for reverting is: Breaks compile on 'win Beta' for
official.desktop.continuous, see https://crbug.com/711712.