Use SkSurfaceValidateRasterInfo in some lesser-used canvas factories

The previous version would reject valid configs (like non-N32 8888).
This changes the results of some unit tests:

- Creating a zero-sized canvas via MakeRasterDirect now fails (like
  it would if you tried to create a zero-sized surface).
- The picture image generator can now produce BGRA and RGBA results,
  regardless of N32, and can produce unpremul.

Bug: skia:
Change-Id: Ifd9fe98adf56748f73eaea01118c928b0a13606b
Reviewed-on: https://skia-review.googlesource.com/c/161120
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed