SkQP: Use SK_GL macro

CQ_INCLUDE_TRYBOTS=skia.primary:Build-Debian9-Clang-x86-devrel-Android_SKQP,Test-Debian9-Clang-NUC7i5BNK-CPU-Emulator-x86-devrel-All-Android_SKQP

Change-Id: I9978cb3c2a2dc726a46d0377f84fceb879b73917
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/237800
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
1 file changed