Move unneeded constants out of header.

The shader-printing constant globals were only used in a single
function, and didn't need to be exposed at global scope.

Change-Id: Ib971be38f08c0623c16b8cd561a44b7e42076981
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/744665
Reviewed-by: Nicolette Prevost <nicolettep@google.com>
Commit-Queue: Nicolette Prevost <nicolettep@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2 files changed