Fix bug & add code to catch ImageFilter clearing bugs

Fix bug & add code to catch ImageFilter clearing bugs

Follow on to https://codereview.chromium.org/1969193002/ (SkPictureImageFilter - clear local canvas before use)

BUG=610667
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1972213002

Committed: https://skia.googlesource.com/skia/+/3806b8fb7ffe757cf42f13024dbaf9f24856ccd3

[robertphillips, 2016-05-12 15:14:55]

Description was changed from

==========
Fix bug & add code to catch ImageFilter clearing bugs
==========

to

==========
Fix bug & add code to catch ImageFilter clearing bugs
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[robertphillips, 2016-05-12 15:16:00]

Description was changed from

==========
Fix bug & add code to catch ImageFilter clearing bugs
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
Fix bug & add code to catch ImageFilter clearing bugs

Follow on to https://codereview.chromium.org/1969193002/ (SkPictureImageFilter -
clear local canvas before use)

GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[robertphillips, 2016-05-12 15:16:00]

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

[robertphillips, 2016-05-12 15:16:49]

Description was changed from

==========
Fix bug & add code to catch ImageFilter clearing bugs

Follow on to https://codereview.chromium.org/1969193002/ (SkPictureImageFilter -
clear local canvas before use)

GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
Fix bug & add code to catch ImageFilter clearing bugs

Follow on to https://codereview.chromium.org/1969193002/ (SkPictureImageFilter -
clear local canvas before use)

BUG=610667

GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[robertphillips, 2016-05-12 15:26:31]

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

[Stephen White, 2016-05-12 15:43:58]

https://codereview.chromium.org/1972213002/diff/1/src/core/SkSpecialSurface.cpp
File src/core/SkSpecialSurface.cpp (right):

https://codereview.chromium.org/1972213002/diff/1/src/core/SkSpecialSurface.c...
src/core/SkSpecialSurface.cpp:78: fCanvas->clear(SK_ColorRED);  // catch any
imageFilter sloppiness
This is a good idea, but I'm not sure we should do this in Debug, since it'll
change behaviour. Are there other areas in GPU where we have different pixel
results in Debug to detect errors? Maybe keep this behind a different #ifdef?

[robertphillips, 2016-05-12 17:00:57]

https://codereview.chromium.org/1972213002/diff/1/src/core/SkSpecialSurface.cpp
File src/core/SkSpecialSurface.cpp (right):

https://codereview.chromium.org/1972213002/diff/1/src/core/SkSpecialSurface.c...
src/core/SkSpecialSurface.cpp:78: fCanvas->clear(SK_ColorRED);  // catch any
imageFilter sloppiness
On 2016/05/12 15:43:58, Stephen White wrote:
> This is a good idea, but I'm not sure we should do this in Debug, since it'll
> change behaviour. Are there other areas in GPU where we have different pixel
> results in Debug to detect errors? Maybe keep this behind a different #ifdef?

Done. Now enabled by SK_IS_BOT.

[Stephen White, 2016-05-12 17:01:49]

LGTM

[robertphillips, 2016-05-12 17:20:34]

The CQ bit was checked by robertphillips@google.com to run a CQ dry run

[commit-bot: I haz the power, 2016-05-12 17:20:44]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1972213002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1972213002/20001

[commit-bot: I haz the power, 2016-05-12 17:42:16]

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

[commit-bot: I haz the power, 2016-05-12 17:42:17]

Dry run: This issue passed the CQ dry run.

[robertphillips, 2016-05-12 17:45:40]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2016-05-12 17:45:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1972213002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1972213002/20001

[commit-bot: I haz the power, 2016-05-12 17:46:42]

Description was changed from

==========
Fix bug & add code to catch ImageFilter clearing bugs

Follow on to https://codereview.chromium.org/1969193002/ (SkPictureImageFilter -
clear local canvas before use)

BUG=610667

GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
Fix bug & add code to catch ImageFilter clearing bugs

Follow on to https://codereview.chromium.org/1969193002/ (SkPictureImageFilter -
clear local canvas before use)

BUG=610667

GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...

Committed:
https://skia.googlesource.com/skia/+/3806b8fb7ffe757cf42f13024dbaf9f24856ccd3
==========

[commit-bot: I haz the power, 2016-05-12 17:46:43]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/3806b8fb7ffe757cf42f13024dbaf9f24856ccd3