Add GrContext::resetGLTextureBindings().

This function binds texture ID 0 to any texture unit/target combo that
Skia has modified.

Bug: chromium:926017
Change-Id: I3ac8f8050c863232886102886e60d3b91a5380c9
Reviewed-on: https://skia-review.googlesource.com/c/190663
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
12 files changed