gsk: Clean up standalone headers
We require folks to include gskglrenderer.h in order to create a GL renderer. So we be careful to only include header in gskglrenderer.h that won't trigger ugly warnings.
See !6363 (closed)
We require folks to include gskglrenderer.h in order to create a GL renderer. So we be careful to only include header in gskglrenderer.h that won't trigger ugly warnings.
See !6363 (closed)