Remove old src/gpu/gl/GrGLDefines.h

I believe this was intended to be done in https://skia-review.googlesource.com/c/skia/+/528156,
but was missed for some reason.

Change-Id: I3b187103c2366b3f020df1b33af5ccd00599fa31
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/705016
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
30 files changed