re-land of new SkSL precisions

Bug: skia:
Change-Id: Ic1deb3db2cbda6ca45f93dee99832971a36a2119
Reviewed-on: https://skia-review.googlesource.com/47841
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/gpu/GrFragmentProcessor.h b/src/gpu/GrFragmentProcessor.h
index 3237684..0c3efd1 100644
--- a/src/gpu/GrFragmentProcessor.h
+++ b/src/gpu/GrFragmentProcessor.h
@@ -18,7 +18,7 @@
 class GrShaderCaps;
 class GrSwizzle;
 
-/** Provides custom fragment shader code. Fragment processors receive an input color (float4) and
+/** Provides custom fragment shader code. Fragment processors receive an input color (half4) and
     produce an output color. They may reference textures and uniforms. They may use
     GrCoordTransforms to receive a transformation of the local coordinates that map from local space
     to the fragment being processed.