Add headers to SkSL GN file.

This makes it easier to work with SkSL files when using an IDE.

Change-Id: I30665478a9cde63b4c9ba7e5a9948e9647f7ef81
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/293571
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed