Don't flush pipeline state when querying sample locations in GL

This was a relic from back when we could use EXT_raster_multisample.
Since MSAA is now always baked into the framebuffer attachments, this
is no longer necessary.

Bug: skia:
Change-Id: I47c66fcdbd008e057dab5eae457bb70ec8e6bb9f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/208460
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
13 files changed