Allow Mock GrBackendTextures to masquerade as GL
Allow Mock GrBackendTextures to masquerade as GL

Change-Id: I13be29dfdc6d3750ca996ad3a03c75befceadc5f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/204221
Reviewed-by: Brian Salomon <61fabaaf0876044aeedfd8e351e485c028d69e7b@google.com>
Commit-Queue: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

aosp-mirror/platform_external_skia,rubenvb/skia,google/skia,rubenvb/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,rubenvb/skia,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,google/skia,rubenvb/skia,google/skia,rubenvb/skia,rubenvb/skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,rubenvb/skia,google/skia,rubenvb/skia