Revert "Limit GL_TEXTURE_RECTANGLE filtering to bilinear."

This reverts commit 4d53c44aa6e8e0d1b6537f83e4287e5a1423ac75.

Reason for revert: Depends on https://skia-review.googlesource.com/c/4383/ which I need to revert.

Original change's description:
> Limit GL_TEXTURE_RECTANGLE filtering to bilinear.
> 
> Adds a clamp for GrTexture filtering that can be set by a subclass at construction. The clamping is performed by GrTextureParams. GrGLTexture limits filtering to bilinear for rectangle and external textures.
> 
> Also moves samplerType() to GrTexturePriv from GrTexture.
> 
> BUG=skia:5932
> 
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4352
> 
> Change-Id: I1f023d4f4133e7eb393367580c0558257e56c8db
> Reviewed-on: https://skia-review.googlesource.com/4352
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Chris Dalton <csmartdalton@google.com>
> 

TBR=bsalomon@google.com,csmartdalton@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=662630

Change-Id: I012aa208594ccff0bb81bece8110a38e1f83ae00
Reviewed-on: https://skia-review.googlesource.com/4444
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
10 files changed