Revert "Reland "Revert "Use ManagedBackendTexture in place of TestUtils backend texture helpers."""

This reverts commit 4efaf5e9feada3eddf286fb362f60d3b11a24e34.

Cq-Include-Trybots: luci.skia.skia.primary:Test-Win10-MSVC-Golo-GPU-QuadroP400-x86_64-Debug-All-Direct3D,Test-Win10-Clang-ShuttleA-GPU-RadeonHD7770-x86_64-Debug-All-Direct3D
Change-Id: I0f5f1c427e8892a67b027b0fbe4863d9fcee2363
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/325863
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
26 files changed