Remove SkField, it's no longer used

Bug: skia:
Change-Id: I8efcbb09dce2cb0e4f33a10e4ff2148058c6fbc5
Reviewed-on: https://skia-review.googlesource.com/c/193362
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed