Tweak API fuzzers to run better in libfuzzer

Prevents logging from cluttering the stats.
Better handles limited memory.

Bug: skia:
Change-Id: I12c1a46875fd9120938cab520ef70de69c451ad8
Reviewed-on: https://skia-review.googlesource.com/110642
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
4 files changed