Revert "Add pooling support on iOS."

This reverts commit 38a93e622b8cb6888d97551ac165406694342c7b.

Reason for revert: need revert first pool change

Original change's description:
> Add pooling support on iOS.
>
> This replaces the `thread_local` attribute with `pthread_setspecific`
> and `pthread_getspecific`. I don't have easy access to iOS 8/9 for
> testing purposes, but on Mac OS X, this implementation works and
> benchmarks the same as the `thread_local` implementation.
>
> Change-Id: I86db88c24d59d946adb66141b32733ebf5261c76
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/328837
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>
> Auto-Submit: John Stiles <johnstiles@google.com>

TBR=brianosman@google.com,adlai@google.com,johnstiles@google.com

Change-Id: Ic06f9e32e524b2be601ee21a5da605fd19aaa64b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/329164
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
1 file changed