change back to method for localmatrix imagefilter

change back to method for localmatrix imagefilter

This method is different from MatrixFilter, in that MatrixFilter does not require a pre-existing
filter, but LocalM does. Also change the comment to be more general, as there is no promise that
we return a different subclass, and certainly not a specific subclass.

This pattern of obj->newWithModifiers() also more closely matches the pattern in SkImage (newSubset).

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/94dd7a52d3fe0632cd830f2e9cd14103c2726aac

[reed1, 2015-10-14 14:23:41]

reed@google.com changed reviewers:
+ robertphillips@google.com, senorblanco@google.com

[reed1, 2015-10-14 14:23:41]

ptal

I didn't notice the api change last night when I reviewed the prev. CL. Sorry
for the churn.

[reed1, 2015-10-14 14:23:46]

The CQ bit was checked by reed@google.com

[commit-bot: I haz the power, 2015-10-14 14:23:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402133002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402133002/1

[commit-bot: I haz the power, 2015-10-14 14:23:53]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-10-14 20:23 UTC

[Stephen White, 2015-10-14 14:26:31]

senorblanco@chromium.org changed reviewers:
+ senorblanco@chromium.org

[Stephen White, 2015-10-14 14:26:31]

https://codereview.chromium.org/1402133002/diff/1/src/core/SkImageFilter.cpp
File src/core/SkImageFilter.cpp (right):

https://codereview.chromium.org/1402133002/diff/1/src/core/SkImageFilter.cpp#...
src/core/SkImageFilter.cpp:444: return SkLocalMatrixImageFilter::Create(matrix,
const_cast<SkImageFilter*>(this));
Could we make this method non-const, instead of const-casting?

[reed1, 2015-10-14 14:28:10]

On 2015/10/14 14:26:31, Stephen White wrote:
> https://codereview.chromium.org/1402133002/diff/1/src/core/SkImageFilter.cpp
> File src/core/SkImageFilter.cpp (right):
> 
>
https://codereview.chromium.org/1402133002/diff/1/src/core/SkImageFilter.cpp#...
> src/core/SkImageFilter.cpp:444: return
SkLocalMatrixImageFilter::Create(matrix,
> const_cast<SkImageFilter*>(this));
> Could we make this method non-const, instead of const-casting?

No, since imagefilters must always be const. The disconnect in this case is that
the input[] parameter to the base constructor does not take const filters. I'm
ok with the cast, but if you want to follow-up with a change to the input
parameter, that's fine with me.

[Stephen White, 2015-10-14 14:29:21]

OK, LGTM.

[reed1, 2015-10-14 14:32:11]

I'll add a comment to this effect at the site of the cast, so the next reader is
not confused.

[reed1, 2015-10-14 14:37:10]

The CQ bit was checked by reed@google.com

[reed1, 2015-10-14 14:37:10]

The patchset sent to the CQ was uploaded after l-g-t-m from
senorblanco@chromium.org
Link to the patchset: https://codereview.chromium.org/1402133002/#ps20001
(title: "add comment for const-cast")

[commit-bot: I haz the power, 2015-10-14 14:37:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402133002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402133002/20001

[commit-bot: I haz the power, 2015-10-14 14:49:37]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/94dd7a52d3fe0632cd830f2e9cd14103c2726aac