Fix bug in protected content validation 1. It is valid for a protected context to sample from an unprotected texture 2. It is necessary to match protected state of framebuffer attachment and the context Bug: angleproject:6602 Change-Id: Ia3138c1a6dc46ff6b85fc5948c6a04ef48fba8a8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3430241 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>