New approach to fixing Vulkan MSAA.

MakeFromBackendTextureAsRenderTarget is planned to be deprecated, so we
should use MakeFromBackendTexture with a sampleCount parameter instead.
On Vulkan, this ran into issues because we assumed an allocation for the
VkImage and the swapchain doesn't provide us with one. Fixed so we don't
need an allocation for Borrowed textures.

Bug: skia:
Change-Id: Ib26888020e093f4a734a4159eae898539c2273b7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/226839
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
6 files changed