Remove SkRefDict.

It is unused. Remove it.

Change-Id: If62a93a58d21bfccd6df112e92a709bff4d11c97
Reviewed-on: https://skia-review.googlesource.com/141566
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
5 files changed