Revert of Fix UB function problems for shaders and mask.

Revert of Fix UB function problems for shaders and mask. (patchset #3 id:40001 of https://codereview.chromium.org/1530743002/ )

Reason for revert:
Breaks man gold tests.

Original issue's description:
> Fix UB function problems for shaders and mask.
> 
> BUG=skia:4634
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1530743002
> 
> Committed: https://skia.googlesource.com/skia/+/dafd044e4aea529f88d899247678d4549f776388

TBR=mtklein@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4634
Committed: https://skia.googlesource.com/skia/+/1e810b3cc290b5b5d95c7789661271256288977c

[herb_g, 2015-12-18 16:50:01]

Created Revert of Fix UB function problems for shaders and mask.

[commit-bot: I haz the power, 2015-12-18 16:50:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1534243002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1534243002/1

[commit-bot: I haz the power, 2015-12-18 16:50:10]

Description was changed from

==========
Revert of Fix UB function problems for shaders and mask. (patchset #3 id:40001
of https://codereview.chromium.org/1530743002/ )

Reason for revert:
Breaks man gold tests.

Original issue's description:
> Fix UB function problems for shaders and mask.
> 
> BUG=skia:4634
> GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
> 
> Committed:
https://skia.googlesource.com/skia/+/dafd044e4aea529f88d899247678d4549f776388

TBR=mtklein@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4634
==========

to

==========
Revert of Fix UB function problems for shaders and mask. (patchset #3 id:40001
of https://codereview.chromium.org/1530743002/ )

Reason for revert:
Breaks man gold tests.

Original issue's description:
> Fix UB function problems for shaders and mask.
> 
> BUG=skia:4634
> GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
> 
> Committed:
https://skia.googlesource.com/skia/+/dafd044e4aea529f88d899247678d4549f776388

TBR=mtklein@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4634

Committed:
https://skia.googlesource.com/skia/+/1e810b3cc290b5b5d95c7789661271256288977c
==========

[commit-bot: I haz the power, 2015-12-18 16:50:11]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/1e810b3cc290b5b5d95c7789661271256288977c