Revert of Improve tracking of bound FBOs in GrGLGpu. (patchset #6 id:100001 of https://codereview.chromium.org/949263002/)

Reason for revert:
breaking hd2000 windows bots

Original issue's description:
> Improve tracking of bound FBOs in GrGLGpu.
>
> Committed: https://skia.googlesource.com/skia/+/d2ad8eb5801e2c8c0fa544a6a776bb46eedde2a0

TBR=egdaniel@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/964543002
4 files changed