stuff

BUG=skia:

Review URL: https://codereview.chromium.org/655913003
Revert of Use approximate scratch textures for image filters. (patchset #1 id:1 of https://codereview.chromium.org/679113004/)

Reason for revert:
Images change on some machines. Mostly look OK but not sure about imagefiltersbase on N5.

Old"
http://chromium-skia-gm.commondatastorage.googleapis.com/gm/bitmap-64bitMD5/imagefiltersbase/11449357083048653160.png

New:
http://chromium-skia-gm.commondatastorage.googleapis.com/gm/bitmap-64bitMD5/imagefiltersbase/14279906119350384263.png

Original issue's description:
> Use approximate scratch textures for image filters.
>
> Committed: https://skia.googlesource.com/skia/+/96c60686eef6fc514feba6136f1b475f71dbf3ec

TBR=senorblanco@google.com,senorblanco@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/664823003
Fix bounds computation of all 0-input filters.

The SkRectShaderImageFilter had the same bug as previously fixed for
SkBitmapSource and SkPictureImageFilter. Rather than copy-and-paste
the implementation, this change makes all filters with 0 inputs return
their source bounds, instead of returning false.

BUG=427251

Review URL: https://codereview.chromium.org/681643003
Use approximate scratch textures for image filters.

Committed: https://skia.googlesource.com/skia/+/96c60686eef6fc514feba6136f1b475f71dbf3ec

Review URL: https://codereview.chromium.org/679113004
Rebaseline imagemagnifier and dropshadowimagefilter tests.

BUG=skia:
TBR=hcm@google.com
NOTRY=true

Review URL: https://codereview.chromium.org/685523002
Re-add suppressions for magnifier and dropshadow GMs.

Brian's change has invalidated the new baselines, so they'll need
to be rebaselined again once his changed has worked its way through.

TBR=bsalomon
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/686573002