If supported, an Sk*Device can take charge of handling of an SkDrawable.
The specific use case right now will be to use this to execute Vulkan
specific SkDrawable's that need to know information about our Vulkan state
and objects at the time the SkDrawable is executed. If a device does not
support the SkDrawable we fall back to the cavans version like we did
previously.
BUG=skia:
Change-Id: I821fa600a80ff645412f296be36990ef390ae0a9
Reviewed-on: https://skia-review.googlesource.com/c/7740
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
