Revert "Make GrRRectBlurEffect use the thread-safe uniquely-keyed view cache"

This reverts commit 4cf00a814f7d8e6428a10441930515f5a6a527e3.

Reason for revert: ANGLE and Mali 400 unhappy.

Original change's description:
> Make GrRRectBlurEffect use the thread-safe uniquely-keyed view cache
>
> This yields a ~8% performance improvement on OOP-R/DDL-like rendering of the simpleblurroundrect GM.
>
> Bug: 1108408
> Change-Id: I1ec9477dffe870e5973f8a334a65b1013a4ca3dd
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/311720
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

TBR=egdaniel@google.com,robertphillips@google.com,adlai@google.com

Change-Id: Ib7135a2244b956d1a5d06c12a2b4c2ce398b9db2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1108408
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/320817
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
5 files changed