remove deprecated SkPixelSerializer

Bug: skia:
Change-Id: I25d33517f1ec7c08551c79d03763c676d1a662f5
Reviewed-on: https://skia-review.googlesource.com/86360
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
14 files changed