remove duplicate SkBase64.h

There's already an identical header in include/utils/SkBase64.h.
(And it's used by Flutter, so we need to keep the include/ one.)

Change-Id: Ia86f5b18d4351ec871902d0fd0e9f076f5d62fc7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209664
Commit-Queue: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
2 files changed