Revert "Revert "Make SkSL GLSL generator declare sk_FragColor inout when EXT fb fetch is used.""

This reverts commit d40133092ae138b3d47a1158101faec3c53c6b1f.

Bug: skia:
Change-Id: I236505da047d5ad29e4952d8955eb7aa1bfb870b
Reviewed-on: https://skia-review.googlesource.com/118621
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
9 files changed