Fix TooltipAura initial sizing.

Fix TooltipAura initial sizing.

r296874 regressed initial tooltip sizing on Aura.
(Widget::SetContentsView sizes the view to the widget)

Reorder the View sizing to after the Widget init.

BUG=418456
TEST=The first Linux Aura tooltip is sized correctly.
R=sky@chromium.org

Committed: https://crrev.com/a5cdf5ead358ca6ae98deadafc99ddaa06465e23
Cr-Commit-Position: refs/heads/master@{#297281}

[msw, 2014-09-29 20:56:12]

msw@chromium.org changed reviewers:
+ sky@chromium.org

[msw, 2014-09-29 20:56:12]

msw@chromium.org changed reviewers:
+ sky@chromium.org

[msw, 2014-09-29 20:57:08]

Hey Scott, please take a look; thanks!

[sky, 2014-09-29 21:24:05]

LGTM

[msw, 2014-09-29 21:24:37]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2014-09-29 21:25:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/613753003/1

[commit-bot: I haz the power, 2014-09-29 21:59:50]

Committed patchset #1 (id:1) as 6969e6c3e2404dacef26c0d6de97cdbcbce6dbab

[commit-bot: I haz the power, 2014-09-29 22:03:50]

Patchset 1 (id:??) landed as
https://crrev.com/a5cdf5ead358ca6ae98deadafc99ddaa06465e23
Cr-Commit-Position: refs/heads/master@{#297281}