Fix WeakPtrFactory member in OneClickSigninBubbleControllerTest

Fix WeakPtrFactory member in OneClickSigninBubbleControllerTest

This forces WeakPtrs to be invalidated before other members' destructors run.
See the bug or the documentation of WeakPtrFactory for more information. I'm
in the process of trying to turn on a clang check for this (see the bug).

BUG=303818
R=groby@chromium.org

Committed: https://crrev.com/4bf6c581c24a100ce3dd4898aa870ff8f7daa37f
Cr-Commit-Position: refs/heads/master@{#311381}

[groby-ooo-7-16, 2015-01-14 00:00:06]

LGTM. If you think the clang check might take longer, you might want to update
the comment on WeakPtrFactory to explicitly state that it needs to be declared
after all other members using it.

[dmichael (off chromium), 2015-01-14 00:07:22]

On 2015/01/14 00:00:06, groby wrote:
> LGTM. If you think the clang check might take longer, you might want to update
> the comment on WeakPtrFactory to explicitly state that it needs to be declared
> after all other members using it.
I've *almost* caught 'em all, so I'll leave out the comment. Here's the CL that
turns on the flag: https://codereview.chromium.org/803603003/
Looks like there's another one on Win, and I have to land the last fixes
separately from that CL. But it's this || close. Thanks for the review!

[dmichael (off chromium), 2015-01-14 00:07:33]

The CQ bit was checked by dmichael@chromium.org

[commit-bot: I haz the power, 2015-01-14 00:08:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/803963005/1

[groby-ooo-7-16, 2015-01-14 00:30:31]

On 2015/01/14 00:07:22, dmichael wrote:
> On 2015/01/14 00:00:06, groby wrote:
> > LGTM. If you think the clang check might take longer, you might want to
update
> > the comment on WeakPtrFactory to explicitly state that it needs to be
declared
> > after all other members using it.
> I've *almost* caught 'em all, so I'll leave out the comment. Here's the CL
that
> turns on the flag: https://codereview.chromium.org/803603003/
> Looks like there's another one on Win, and I have to land the last fixes
> separately from that CL. But it's this || close. Thanks for the review!

That's awesome news! Can't wait to see it in action!

[commit-bot: I haz the power, 2015-01-14 01:04:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-14 01:07:20]

Patchset 1 (id:??) landed as
https://crrev.com/4bf6c581c24a100ce3dd4898aa870ff8f7daa37f
Cr-Commit-Position: refs/heads/master@{#311381}