Sk4px: SrcATop, DstATop, Xor, Multiply

Sk4px: SrcATop, DstATop, Xor, Multiply

SSE runs 2-3x faster (than 4f), NEON runs 1.2-1.4x faster (than existing NEON).

Small diffs on {aarectmodes, imagefilters_xfermodes, hairmodes, mixed_xfermodes} only on AA edges due to precision drop.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/2d8d33e9e825f9919875be64a71b746189b385be

[mtklein_C, 2015-05-13 19:56:37]

mtklein@chromium.org changed reviewers:
+ reed@google.com

[mtklein_C, 2015-05-13 19:56:42]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-05-13 19:57:04]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1132853005/1

[commit-bot: I haz the power, 2015-05-13 20:02:48]

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

[commit-bot: I haz the power, 2015-05-13 20:02:49]

Dry run: This issue passed the CQ dry run.

[mtklein, 2015-05-13 20:20:41]

The CQ bit was checked by mtklein@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-05-13 20:21:00]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1132853005/20001

[commit-bot: I haz the power, 2015-05-13 20:27:12]

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

[commit-bot: I haz the power, 2015-05-13 20:27:14]

Dry run: This issue passed the CQ dry run.

[reed1, 2015-05-13 21:07:45]

lgtm

[mtklein, 2015-05-13 21:08:05]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-05-13 21:08:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1132853005/20001

[commit-bot: I haz the power, 2015-05-13 21:08:54]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/2d8d33e9e825f9919875be64a71b746189b385be