Clear the cached avatar button offset when the DPI scaling changes

Listen to the Windows DPI scaling change message and force the user-avatar offset position to be recalculated.

BUG=609398
Review-Url: https://codereview.chromium.org/2881563004
Cr-Commit-Position: refs/heads/master@{#472100}
Committed: https://chromium.googlesource.com/chromium/src/+/0fe78b97dbbd03e9e08d676085f80a991d767d1f

[kylix_rd, 2017-05-12 15:57:07]

Description was changed from

==========
Clear the cached button x delta


Initial scaffolding for listening to dpi changes

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

to

==========
Listen to the Windows DPI scaling change message and force the user-avatar
offset position to be recalculated.

BUG=609398
==========

[kylix_rd, 2017-05-12 15:57:07]

kylixrd@chromium.org changed reviewers:
+ pkasting@chromium.org

[kylix_rd, 2017-05-12 15:57:49]

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

[commit-bot: I haz the power, 2017-05-12 15:58:26]

Dry run: CQ is trying da patch.

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

[kylix_rd, 2017-05-12 16:02:23]

In theory, this patch should work. I've not been able to properly test this
since it requires having two monitors with different resolutions *and* different
scaling factors. Two monitors with the same resolution and changing the scaling
factor on one of them doesn't seem to demonstrate the problem. What really seems
to show this is when one monitor is 4K at 1.5-2x scaling and the other is a 2K
or 3K at 1.0x scaling.

[commit-bot: I haz the power, 2017-05-12 16:45:52]

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

[commit-bot: I haz the power, 2017-05-12 16:45:52]

Dry run: This issue passed the CQ dry run.

[Peter Kasting, 2017-05-12 21:06:16]

LGTM

[kylix_rd, 2017-05-16 13:54:50]

The CQ bit was checked by kylixrd@chromium.org

[commit-bot: I haz the power, 2017-05-16 13:55:09]

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, 2017-05-16 14:38:23]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1494942890924680, "parent_rev":
"cc872706b26db043caa7d57f4c10661ff9d0ae40", "commit_rev":
"0fe78b97dbbd03e9e08d676085f80a991d767d1f"}

[commit-bot: I haz the power, 2017-05-16 14:38:35]

Description was changed from

==========
Listen to the Windows DPI scaling change message and force the user-avatar
offset position to be recalculated.

BUG=609398
==========

to

==========
Listen to the Windows DPI scaling change message and force the user-avatar
offset position to be recalculated.

BUG=609398

Review-Url: https://codereview.chromium.org/2881563004
Cr-Commit-Position: refs/heads/master@{#472100}
Committed:
https://chromium.googlesource.com/chromium/src/+/0fe78b97dbbd03e9e08d676085f8...
==========

[commit-bot: I haz the power, 2017-05-16 14:38:36]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/0fe78b97dbbd03e9e08d676085f8...