Revert "Add ImageToColorSpace helper in SkImageFilter"

Revert "Add ImageToColorSpace helper in SkImageFilter"

This reverts commit e02d3caab823728d3106bcb1d4fbb674afc959fb.

Reason for revert: New logic triggers out-of-date assert. Reverting until I can fix that, too.

Original change's description:
> Add ImageToColorSpace helper in SkImageFilter
>
> Share this logic among a couple filters that need it. This also fixes a
> bug that showed up in the morhpology GM for GPU color space configs.
>
> BUG=skia:
>
> Change-Id: Ic686b07aff80e58e14a86108703bfbb3cf524979
> Reviewed-on: https://skia-review.googlesource.com/6475
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>
>

TBR=bsalomon@google.com,robertphillips@google.com,brianosman@google.com,reviews@skia.org
BUG=skia:
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I00b444dfaaa9b5981f7b33b34419cf9795b52ddb
Reviewed-on: https://skia-review.googlesource.com/6480
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>