Add option to disable vsync on viewer unix.

This also fixes an issue where vulkan would crash any time we change a
display param on unix.

Bug: skia:
Change-Id: Ic6c3843e04bc77c2e9c5301ee38fcc58a409495d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/203380
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
6 files changed