add benchType deserial to time deserializing pictures

Piece of the larger effort to merge readbuffer and validatingreadbuffer

Bug: skia:
Change-Id: I79305e27c4712c3b91d213d09d6c2ef24b86e671
Reviewed-on: https://skia-review.googlesource.com/81120
Commit-Queue: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
3 files changed