Make these more consistent with the rest of the wrapper classes.
Also handle some VkResult errors that were being ignored.

Will pave the way for better handling of buffer allocation error
conditions.

Bug: chromium:1086532
Change-Id: Idc5b3f0e2945b1f44f152d33e8cc572f83a6b658
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2219136
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Mohan Maiya <m.maiya@samsung.com>