Revert "Always force GPU generated masks be top left"

This reverts commit 0b7ce069f2bb4cf73f171bf2aca1dff4e4b8a7b1.

Reason for revert: Nexus 7 is failing

Original change's description:
> Always force GPU generated masks be top left
> 
> Bug: 878195
> Change-Id: Ie5e89753c2251ee1b4bd60ac2b02cedb7f5292f7
> Reviewed-on: https://skia-review.googlesource.com/150133
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

TBR=bsalomon@google.com,robertphillips@google.com

Change-Id: I985c9c7fbfa4ca8c09ba7f716d57b9763a589619
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 878195
Reviewed-on: https://skia-review.googlesource.com/150366
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
2 files changed