Centre message windows when they are shown.

Centre message windows when they are shown.

This adds a missing optional parameter to resizeWindowToContent. The parameter
is already specified when the message is updated--not including it here too was
an oversight.

Committed: https://crrev.com/9a2648963341a87deb70d2e4d5eae13884b3ef75
Cr-Commit-Position: refs/heads/master@{#329202}

[Jamie, 2015-05-08 20:41:11]

jamiewalch@chromium.org changed reviewers:
+ kelvinp@chromium.org

[Jamie, 2015-05-08 20:41:12]

ptal

[kelvinp, 2015-05-11 17:13:51]

lgtm

[Jamie, 2015-05-11 17:32:13]

The CQ bit was checked by jamiewalch@chromium.org

[commit-bot: I haz the power, 2015-05-11 17:33:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1133873002/1

[commit-bot: I haz the power, 2015-05-11 18:43:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-11 18:45:12]

Patchset 1 (id:??) landed as
https://crrev.com/9a2648963341a87deb70d2e4d5eae13884b3ef75
Cr-Commit-Position: refs/heads/master@{#329202}