Add 'Save to SKP' option to Viewer

Bug: skia:
Change-Id: Iea3794ce8710c84f2529b78b21655f2bf6aaa90e
Reviewed-on: https://skia-review.googlesource.com/79160
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed