Move uniform buffers over to new vulkan buffer class.

Bug: skia:11226
Change-Id: Ia6a0e86722bc718e6827c0da8ee5035d90a2deb9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/365536
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
18 files changed