Revert "Allow swapping out of GrBackendTexture used by SkSurface"

This reverts commit 9456f7aba5ccc8dff81b5bbcbcfec5f593195083.

Reason for revert: Breaking layout tests

Original change's description:
> Allow swapping out of GrBackendTexture used by SkSurface
> 
> Change-Id: I67f26efaee87536f3faf51ca164bf003013c7c8a
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215428
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

TBR=egdaniel@google.com,bsalomon@google.com,robertphillips@google.com

Change-Id: I0ff5e63d47cd3e536f9fe656503d74965ce6dbfd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215822
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
10 files changed