Revert "Revert "Always make SkImageShaders in heap.""

Revert "Revert "Always make SkImageShaders in heap.""

This reverts commit 07f665efb918f68e406b76a78d0b76d5c714f16c.

Reason for revert: Android code moved from priv api to real api

Original change's description:
> Revert "Always make SkImageShaders in heap."
>
> This reverts commit ff590a12441002d281254ec6a86070ac0a19263f.
>
> Reason for revert: This breaks the android roll because they are using
> a private call. Updating android tests to use new api.
>
> Original change's description:
> > Always make SkImageShaders in heap.
> >
> > I made a couple of measurments, and it looks like any differences is
> > well below the noise threshold.
> >
> > Just for the record run1: .9991 of baseline and run2 .9988 of baseline.
> > I was using top25 .skps as workload.
> >
> > TBR=mtklein@google.com
> >
> > Change-Id: If4fa06e5d5df72fb67dbb4bbb99c926f05765897
> > Reviewed-on: https://skia-review.googlesource.com/8341
> > Reviewed-by: Herb Derby <herb@google.com>
> > Commit-Queue: Herb Derby <herb@google.com>
> >
>
> TBR=mtklein@chromium.org,mtklein@google.com,herb@google.com,reviews@skia.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
>
> Change-Id: Ibdaafc796702e250933b62e5f4abb5e2ce8d40c0
> Reviewed-on: https://skia-review.googlesource.com/8393
> Commit-Queue: Herb Derby <herb@google.com>
> Reviewed-by: Herb Derby <herb@google.com>
>

TBR=mtklein@chromium.org,mtklein@google.com,herb@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I320b5ebf707d74ffafd8b70d69646b74a30f0ae8
Reviewed-on: https://skia-review.googlesource.com/8407
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Herb Derby <herb@google.com>