Revert of SkImage-backed SkPictureShader (patchset #4 id:60001 of https://codereview.chromium.org/1343153003/ )

Reason for revert:
This CL appears to be breaking the pictureshader, pictureshadertile and tiled_picture_shader GMs on the iPad4 and the N7. The artifact is black rectangles.

Original issue's description:
> SkImage-backed SkPictureShader
>
> Instead of using an explicit image generator + SkBitmap + bitmap shader,
> switch to the shiny new SkImage/image generator/image shader.
>
> R=reed@google.com
>
> Committed: https://skia.googlesource.com/skia/+/97be9a0c86eedd8ab85ae7d9aaccb0b0a8e4577d

TBR=reed@google.com,fmalita@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1374763003
1 file changed