Revert "Check for ANGLE's implementation of texture_rectangle"

This reverts commit 00f8866a321332f07520e3c12963aa1332bb7e82.

Reason for revert: Seems to be breaking angle test bots. Eg:
https://chromium-swarm.appspot.com/task?id=3dcb7f58728de610&refresh=10

Original change's description:
> Check for ANGLE's implementation of texture_rectangle
> 
> ANGLE has implemented extension to support for texture_rectangle. Check
> for its existence as well as GL_ARB_texture_rectangle extension.
> 
> Intended to follow up on Chrome side to avoid copy into texture 2d for
> PaintCanvasVideoRenderer.
> 
> Bug: skia:7903
> Change-Id: I450aa7fcd08628831251a9e142fd50719723282d
> Reviewed-on: https://skia-review.googlesource.com/130962
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Weiliang Chen <weiliangc@chromium.org>

TBR=bsalomon@google.com,weiliangc@chromium.org

Change-Id: I9fbf9ff314ffcf3abcc5275bd68124f4b329da21
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:7903
Reviewed-on: https://skia-review.googlesource.com/131060
Reviewed-by: Ravi Mistry <rmistry@google.com>
Commit-Queue: Ravi Mistry <rmistry@google.com>
4 files changed