generalize xferu64 procs using proc4f

generalize xferu64 procs using proc4f

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1686013002

[reed2, 2016-02-10 03:56:03]

Description was changed from

==========
generalize xferu64 procs using proc4f

BUG=skia:
==========

to

==========
generalize xferu64 procs using proc4f

BUG=skia:
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[reed2, 2016-02-10 03:56:42]

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

[commit-bot: I haz the power, 2016-02-10 03:56:48]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1686013002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1686013002/1

[reed2, 2016-02-10 04:02:48]

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

[commit-bot: I haz the power, 2016-02-10 04:29:51]

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

[commit-bot: I haz the power, 2016-02-10 04:29:52]

Dry run: This issue passed the CQ dry run.

[mtklein, 2016-02-10 16:19:34]

https://codereview.chromium.org/1686013002/diff/1/src/core/SkXfermodeU64.cpp
File src/core/SkXfermodeU64.cpp (right):

https://codereview.chromium.org/1686013002/diff/1/src/core/SkXfermodeU64.cpp#...
src/core/SkXfermodeU64.cpp:87: template <DstType D> void src_u64_1(const
SkXfermode::U64State& state, uint64_t dst[],
why is this called src_u64_1?  It's not always src mode, is it?

https://codereview.chromium.org/1686013002/diff/1/src/core/SkXfermodeU64.cpp#...
src/core/SkXfermodeU64.cpp:94: d4.store(d.fVec);
Do these stores and loads disappear?  Seems like they can't?

We might try next making SkPM4f be or have an Sk4f.

[reed1, 2016-02-10 19:34:24]

moving this over to https://codereview.chromium.org/1685203002