Dawn: remove persistent TextureView from GrDawnTexture.

For mipmaps, the texture view we need depends on the mipmap mode. In
particular, for mipmap "none" mode, we need a view which ignores
everything but mip 0. So remove the persistent one.

Change-Id: I37a5e8a299edf423b67fd85135d6fbd9d26e62a7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/320636
Commit-Queue: Stephen White <senorblanco@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
5 files changed