Remove dead helper class.
Remove dead helper class.

This was probably used by the old Parser or IRGenerator, but no one
uses it today.

Change-Id: I3d32d022c42a02268bc07ec96acc9dbcc5ceda2b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/573649
Commit-Queue: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>
Auto-Submit: John Stiles <f4fcf42d3bb5924557f1eeb3be66747535e585da@google.com>
Reviewed-by: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>

google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia