Integers can now be passed as uniforms; needed for passing color count to fragment shader

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2076143003

Committed: https://skia.googlesource.com/skia/+/cc3a22b369e1a60fa2acf2987f2934baf7c4b198
Review-Url: https://codereview.chromium.org/2076143003
5 files changed