Implement canComputeFastBounds() for image filters.

Implement canComputeFastBounds() for image filters.

Image filters have never implemented this check, which means that
filters which affect transparent black falsely claim they can compute
their bounds.

Implemented an affectsTransparentBlack() virtual for image 
filters, and a similar helper function for color filters.

This will affect the following GMs: imagefiltersscaled 
(lighting, perlin noise now filter to clip), 
colorfilterimagefilter (new test case), imagefiltersclipped 
(perlin noise now filters to clip).

Note: I de-inlined SkPaint::canComputeFastBounds() to avoid adding
a dependency from SkPaint.h to SkImageFilter.h.h. Skia benches show
no impact from this change, but will watch the perf bots carefully.

BUG=4212
Committed: https://skia.googlesource.com/skia/+/915881fe743f9a789037695f543bc6ea189cd0cb

[Stephen White, 2015-08-17 16:54:45]

senorblanco@chromium.org changed reviewers:
+ reed@google.com

[Stephen White, 2015-08-17 16:54:53]

reed@: PTAL. Thanks!

[Stephen White, 2015-08-17 17:29:10]

The CQ bit was checked by senorblanco@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-17 17:29:22]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296943002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296943002/20001

[commit-bot: I haz the power, 2015-08-17 17:36:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-17 17:36:04]

Dry run: This issue passed the CQ dry run.

[Stephen White, 2015-08-17 20:43:03]

The CQ bit was checked by senorblanco@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-17 20:43:22]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296943002/40002
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296943002/40002

[commit-bot: I haz the power, 2015-08-17 20:49:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-17 20:49:46]

Dry run: This issue passed the CQ dry run.

[Stephen White, 2015-08-18 15:37:31]

The CQ bit was checked by senorblanco@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-18 15:37:43]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296943002/70001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296943002/70001

[commit-bot: I haz the power, 2015-08-18 15:49:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-18 15:49:26]

Dry run: This issue passed the CQ dry run.

[Stephen White, 2015-08-19 20:42:03]

reed@: Friendly ping. :)

[reed1, 2015-08-19 21:19:24]

seems fine, but I wonder if we can avoid another virtual to add to various
colorfilter subclasses...

https://codereview.chromium.org/1296943002/diff/70001/include/core/SkColorFil...
File include/core/SkColorFilter.h (right):

https://codereview.chromium.org/1296943002/diff/70001/include/core/SkColorFil...
include/core/SkColorFilter.h:143: virtual bool affectsTransparentBlack() const {
Is this different than just calling

if (this->filterColor(0)) {
   ...
}

[Stephen White, 2015-08-19 21:57:08]

New patch up.

https://codereview.chromium.org/1296943002/diff/70001/include/core/SkColorFil...
File include/core/SkColorFilter.h (right):

https://codereview.chromium.org/1296943002/diff/70001/include/core/SkColorFil...
include/core/SkColorFilter.h:143: virtual bool affectsTransparentBlack() const {
On 2015/08/19 21:19:24, reed1 wrote:
> Is this different than just calling
> 
> if (this->filterColor(0)) {
>    ...
> }

Good idea! Done.

[Stephen White, 2015-08-19 22:00:01]

The CQ bit was checked by senorblanco@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-19 22:00:12]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296943002/110001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296943002/110001

[commit-bot: I haz the power, 2015-08-19 22:06:56]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-19 22:06:57]

Dry run: This issue passed the CQ dry run.

[reed1, 2015-08-20 14:06:05]

https://codereview.chromium.org/1296943002/diff/70001/src/core/SkColorFilter.cpp
File src/core/SkColorFilter.cpp (right):

https://codereview.chromium.org/1296943002/diff/70001/src/core/SkColorFilter....
src/core/SkColorFilter.cpp:78: virtual bool affectsTransparentBlack() const
override {
Hmm, I still don't understand the need for a new virtual on colorfilter.

bool affectsTransparentBlack() const {
    return this->filterColor(0) != 0;
}

This can be on the base-class an non-virtual. It will, in-turn call virtuals to
make it correct for all subclasses with no additional work needed in any
subclass.

[Stephen White, 2015-08-20 14:23:32]

https://codereview.chromium.org/1296943002/diff/70001/src/core/SkColorFilter.cpp
File src/core/SkColorFilter.cpp (right):

https://codereview.chromium.org/1296943002/diff/70001/src/core/SkColorFilter....
src/core/SkColorFilter.cpp:78: virtual bool affectsTransparentBlack() const
override {
On 2015/08/20 14:06:05, reed1 wrote:
> Hmm, I still don't understand the need for a new virtual on colorfilter.
> 
> bool affectsTransparentBlack() const {
>     return this->filterColor(0) != 0;
> }
> 
> This can be on the base-class an non-virtual. It will, in-turn call virtuals
to
> make it correct for all subclasses with no additional work needed in any
> subclass.

The changes to this file were reverted in PS6; maybe you're looking at an older
patch?

That said, I'm now calling filterColor(0) everywhere. I kind of like your idea
of putting (non-virtual) affectsTransparentBlack() helper back on SkColorFilter.

[Stephen White, 2015-08-20 14:31:03]

New patch up. PTAL.

[Stephen White, 2015-08-20 14:31:08]

The CQ bit was checked by senorblanco@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-20 14:31:18]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296943002/130001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296943002/130001

[reed1, 2015-08-20 14:34:03]

doh!, you're right about an older patch.

lgtm

[commit-bot: I haz the power, 2015-08-20 14:37:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-20 14:37:40]

Dry run: This issue passed the CQ dry run.

[Stephen White, 2015-08-20 14:41:24]

The CQ bit was checked by senorblanco@chromium.org

[commit-bot: I haz the power, 2015-08-20 14:41:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1296943002/130001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1296943002/130001

[commit-bot: I haz the power, 2015-08-20 14:42:14]

Committed patchset #8 (id:130001) as
https://skia.googlesource.com/skia/+/915881fe743f9a789037695f543bc6ea189cd0cb

[herb_g, 2015-08-20 16:28:31]

A revert of this CL (patchset #8 id:130001) has been created in
https://codereview.chromium.org/1300403003/ by herb@google.com.

The reason for reverting is: This causes a syntax error.

http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp....