Traverse FieldAccess' base expression in visitExpression.

The absence of the FieldAccess::fBase traversal appears to be a simple
oversight. This doesn't appear to affect any tests.

Change-Id: I82a5828acedd00f62bf177bd2cf70d67071a83fa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319413
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
1 file changed