Revert "Add a flag to GrSurfaceFlags that requires the texture to be cleared upon creation. "

This reverts commit 45e5068a6d10f4e4fd4658824310f8871f02ccf7.

Reason for revert: :'(

Original change's description:
> Add a flag to GrSurfaceFlags that requires the texture to be cleared upon creation. 
> 
> Bug: chromium:656320
> 
> Change-Id: I940bfa24540516ab83a2ed52f761b96eb6ad19f1
> Reviewed-on: https://skia-review.googlesource.com/17391
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> 

TBR=egdaniel@google.com,bsalomon@google.com,robertphillips@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Bug: chromium:656320

Change-Id: I8a4f71537e45f3c4cf37b10b2dc8ee38fe6959ba
Reviewed-on: https://skia-review.googlesource.com/17765
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
14 files changed