skip neon intrinsics in libpng when neon is not available

skip neon intrinsics in libpng when neon is not available

Followup to https://codereview.chromium.org/2021403002

BUG=599917, 618061
Committed: https://crrev.com/d66b57b0f0f5e8673612fc58fe9656a6991d6a69
Cr-Commit-Position: refs/heads/master@{#400714}

[Mostyn Bramley-Moore, 2016-06-19 22:24:17]

The CQ bit was checked by mostynb@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2016-06-19 22:24:20]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2074363002/1

[Mostyn Bramley-Moore, 2016-06-19 22:28:41]

mostynb@opera.com changed reviewers:
+ jam@chromium.org, msarett@chromium.org

[Mostyn Bramley-Moore, 2016-06-19 22:28:41]

@jam, msarett: the recent libpng upgrade broke non-neon arm builds.  This should
hopefully fix that.  IIRC the runtime neon detection is deprecated in chromium,
so I only made use of the compile-time neon setting.

[commit-bot: I haz the power, 2016-06-19 23:55:53]

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

[commit-bot: I haz the power, 2016-06-19 23:55:54]

Dry run: This issue passed the CQ dry run.

[msarett, 2016-06-20 12:53:30]

msarett@google.com changed reviewers:
+ msarett@google.com

[msarett, 2016-06-20 12:53:31]

LGTM!

Thanks for this fix!  I didn't realize that Chrome still supports Arm without
Neon.

[jam, 2016-06-20 15:34:51]

lgtm

[Mostyn Bramley-Moore, 2016-06-20 17:29:05]

The CQ bit was checked by mostynb@opera.com

[commit-bot: I haz the power, 2016-06-20 17:29:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2074363002/1

[commit-bot: I haz the power, 2016-06-20 17:36:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-20 17:46:08]

Description was changed from

==========
skip neon intrinsics in libpng when neon is not available

Followup to https://codereview.chromium.org/2021403002

BUG=599917, 618061
==========

to

==========
skip neon intrinsics in libpng when neon is not available

Followup to https://codereview.chromium.org/2021403002

BUG=599917, 618061

Committed: https://crrev.com/d66b57b0f0f5e8673612fc58fe9656a6991d6a69
Cr-Commit-Position: refs/heads/master@{#400714}
==========

[commit-bot: I haz the power, 2016-06-20 17:46:09]

Patchset 1 (id:??) landed as
https://crrev.com/d66b57b0f0f5e8673612fc58fe9656a6991d6a69
Cr-Commit-Position: refs/heads/master@{#400714}