New GM to test SkDrawFilter

We had zero coverage for SkDrawFilter. This new GM draws two rectangles.
If SkDrawFilter is working, they will not match (have different colors
and one will be blurred). If SkDrawFilter is broken, they will match.

R=scroggo@google.com

Committed: https://skia.googlesource.com/skia/+/cdf34cdfb930a876910cffd96f080fce55f003bd

[tomhudson, 2015-03-06 13:45:36]

tomhudson@google.com changed reviewers:
- djsollen@google.com, mtklein@google.com, reed@google.com

[tomhudson, 2015-03-06 13:46:01]

PTAL

[scroggo, 2015-03-06 13:51:41]

lgtm

Could you add some comments in the GM explaining its motivation? I know we've
talked about trimming down our GMs so we don't repeatedly test the same
features. From the code, it's not clear what the goal of the test is; the
check-in comment is a good start.

https://codereview.chromium.org/984883003/diff/20001/gm/drawfilter.cpp
File gm/drawfilter.cpp (right):

https://codereview.chromium.org/984883003/diff/20001/gm/drawfilter.cpp#newcode48
gm/drawfilter.cpp:48: canvas->setDrawFilter(NULL);
Is this line needed?

[tomhudson, 2015-03-06 14:00:05]

On 2015/03/06 13:51:41, scroggo wrote:
> Could you add some comments in the GM explaining its motivation? I know we've
> talked about trimming down our GMs so we don't repeatedly test the same
> features. From the code, it's not clear what the goal of the test is; the
> check-in comment is a good start.

Done.
 
> https://codereview.chromium.org/984883003/diff/20001/gm/drawfilter.cpp
> File gm/drawfilter.cpp (right):
> 
>
https://codereview.chromium.org/984883003/diff/20001/gm/drawfilter.cpp#newcode48
> gm/drawfilter.cpp:48: canvas->setDrawFilter(NULL);
> Is this line needed?

Just being over-cautious.

[scroggo, 2015-03-06 14:01:27]

On 2015/03/06 14:00:05, tomhudson wrote:
> On 2015/03/06 13:51:41, scroggo wrote:
> > Could you add some comments in the GM explaining its motivation? I know
we've
> > talked about trimming down our GMs so we don't repeatedly test the same
> > features. From the code, it's not clear what the goal of the test is; the
> > check-in comment is a good start.
> 
> Done.
>  
> > https://codereview.chromium.org/984883003/diff/20001/gm/drawfilter.cpp
> > File gm/drawfilter.cpp (right):
> > 
> >
>
https://codereview.chromium.org/984883003/diff/20001/gm/drawfilter.cpp#newcode48
> > gm/drawfilter.cpp:48: canvas->setDrawFilter(NULL);
> > Is this line needed?
> 
> Just being over-cautious.

lgtm

[tomhudson, 2015-03-06 14:01:36]

The CQ bit was checked by tomhudson@google.com

[commit-bot: I haz the power, 2015-03-06 14:10:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/984883003/40001

[commit-bot: I haz the power, 2015-03-06 14:15:23]

Committed patchset #3 (id:40001) as
https://skia.googlesource.com/skia/+/cdf34cdfb930a876910cffd96f080fce55f003bd