Partial revert of "Remove SK_GL #ifdefs from GrBackendSurface"

Original CL https://skia-review.googlesource.com/c/skia/+/701398

This was observed to be causing performance issues, however
dependent CLs have already been landed in clients to use the
new APIs. Thus, this keeps the new API interface
(e.g. GrBackendTextures::MakeGL), but moves GrBackendSurface
back to using a type union. This keeps all other uses in Skia
on the new API, so a reland will be easier. Exceptions were
to GrGLGpu.cpp and GrBackendUtils.cpp, which had made use
of the newly exposed subclasses directly via casting.

GrGLBackendTextureInfo is back to using a bare pointer
because to not do so caused an error:

../../../../../../skia/include/core/SkRefCnt.h:151:9: runtime error: upcast of misaligned address 0x000000000009 for type 'GrGLTextureParameters', which requires 8 byte alignment


Change-Id: I4794c3c2a729968c6f73ab21fc076ec74a799859
Bug: b/294504539
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/737937
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
9 files changed