Drop -fno-slp-vectorize from the Clang build

Drop -fno-slp-vectorize from the Clang build

http://llvm.org/PR20354 was fixed and rolled into Chromium in
the latest Clang roll.

BUG=none

Committed: https://crrev.com/5926b3d223f5c183b3341a01b522875aceae2ed9
Cr-Commit-Position: refs/heads/master@{#295564}

[hans, 2014-09-18 16:49:06]

hans@chromium.org changed reviewers:
+ thakis@chromium.org

[hans, 2014-09-18 16:49:07]

Since the Clang roll has been in for a day, maybe it's time to drop this flag?

[Nico, 2014-09-18 17:19:38]

lgtm with green trybots (ScrollOffsetAnimationCurveTest.Duration in particular
is the test that failed last time)

[hans, 2014-09-18 20:18:26]

On 2014/09/18 17:19:38, Nico (hiding) wrote:
> lgtm with green trybots (ScrollOffsetAnimationCurveTest.Duration in particular
> is the test that failed last time)

Tryjobs look good. I specifically looked at
ScrollOffsetAnimationCurveTest.Duration in {mac,linux}_chromium_rel_swarming

[hans, 2014-09-18 20:18:29]

The CQ bit was checked by hans@chromium.org

[commit-bot: I haz the power, 2014-09-18 20:19:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/582583003/1

[commit-bot: I haz the power, 2014-09-18 21:47:56]

Committed patchset #1 (id:1) as e2b1af5aaaef8db141c4603f4dab474472322b40

[commit-bot: I haz the power, 2014-09-18 21:49:09]

Patchset 1 (id:??) landed as
https://crrev.com/5926b3d223f5c183b3341a01b522875aceae2ed9
Cr-Commit-Position: refs/heads/master@{#295564}

[Nico, 2014-09-18 21:52:49]

Sorry, the commit message reminded me that some .gn file should get the same
change…

[hans, 2014-09-18 23:35:22]

On 2014/09/18 21:52:49, Nico (hiding) wrote:
> Sorry, the commit message reminded me that some .gn file should get the same
> change…

I'm the one who should have remembered in the first place. Fix:
https://codereview.chromium.org/585693002