Remove window rects flag from GrInternalSurfaceFlags.

This flag is annoying to set correctly when writing test code.
Fortunately it has become redundant with the "is GL FBO 0" flag.

Change-Id: Ifd88292d2d6ea05bfe0d269e853baff857e70bfe
Reviewed-on: https://skia-review.googlesource.com/c/178929
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
9 files changed