This CL adds tests for decorated variable and updates the API to be
slightly nicer.
Bug: tint:11
Change-Id: I0bd5b8b6e6f682dc9d405e02e51d5dbcaeccc5f3
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/16465
Commit-Queue: Sarah Mashayekhi <sarahmashay@google.com>
Reviewed-by: Sarah Mashayekhi <sarahmashay@google.com>
Dan Sinclair