Add 16-bit P3 png test image

Bug: b/37433905
Change-Id: Ifcbee1879885c6c235d69f924846e34475804f8c
Reviewed-on: https://skia-review.googlesource.com/13770
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Matt Sarett <msarett@google.com>
2 files changed