Revert of Moving SkBlurImageFilter into core (patchset #6 id:100001 of https://codereview.chromium.org/2255803003/ )

Reason for revert:
It looks like this breaks our roll into Google3:
https://test.corp.google.com/ui#id=OCL:130943857:BASE:130944046:1471881622765:61dbdd3

Original issue's description:
> Moving SkBlurImageFilter into core
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2255803003
>
> Committed: https://skia.googlesource.com/skia/+/dd3259eb95c3b47e11eefa3b176365a112a32b48

TBR=reed@google.com,fmalita@chromium.org,vjiaoblack@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review-Url: https://codereview.chromium.org/2263283002
8 files changed