tree 6de38cd425016f9411e5dc20985dee795364ac30
parent c30c418f4eb75f365c7d7a32d5419b41ca780ba8
author mtklein <mtklein@chromium.org> 1461182528 -0700
committer Commit bot <commit-bot@chromium.org> 1461182529 -0700

Revert of SkOnce: 2 bytes -> 1 byte (patchset #4 id:60001 of https://codereview.chromium.org/1904483003/ )

Reason for revert:
bust the roll

Original issue's description:
> SkOnce: 2 bytes -> 1 byte
>
> This uses the same logic we worked out for SkOncePtr to reduce
> the memory footprint of SkOnce from a done byte and lock byte
> to a single 3-state byte:
>
>   - NotStarted: no thread has tried to run fn() yet
>   - Active:     a thread is running fn()
>   - Done:       fn() is complete
>
> Threads which see Done return immediately.
> Threads which see NotStarted try to move to Active, run fn(), then move to Done.
> Threads which see Active spin until the active thread moves to Done.
>
> This additionally fixes a too-weak memory order bug in SkOncePtr,
> and adds a big note to explain.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1904483003
>
> Committed: https://skia.googlesource.com/skia/+/df02d338be8e3c1c50b48a3a9faa582703a39c07

TBR=herb@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1898413004