Revert "Blacklist hanging test."

This reverts commit e3e68cf14f6b202540717020e79fb53be4151c38.

Reason for revert: The test was hanging due to https://skia-review.googlesource.com/c/skia/+/142102, which has been reverted.

Original change's description:
> Blacklist hanging test.
> 
> Blacklist gr_mipmap_build_511x512 for nanobench on the Acer Chromebook
> R13 Convertible to avoid timeouts for Release build.
> 
> Bug: skia:8187
> No-Try: true
> Change-Id: Ic63fb705a6a6cc6576978c96a8dd5206dc59ba0d
> Reviewed-on: https://skia-review.googlesource.com/143162
> Commit-Queue: Brian Osman <brianosman@google.com>
> Auto-Submit: Ben Wagner <benjaminwagner@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

TBR=benjaminwagner@google.com,brianosman@google.com

Change-Id: Id5144f1ada6d2059e473a2891816775ea7fe2663
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:8187
Reviewed-on: https://skia-review.googlesource.com/143320
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
2 files changed