add pathops debugging

add pathops debugging

Pathops has many points of failure, most of which
are triggered by extreme data generated by fuzzers.
It's difficult to figure out which failure point
was triggered when the operation gives up.

Add instrumentation so that the failure can
be debugged when the data is well-behaved.

Also, add a check that looks for a sequence of
coincident points on multiple edges that are out
of order when compared to each other.

TBR=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2274803003

Committed: https://skia.googlesource.com/skia/+/025b11ecde8733d9b3eee54e132cc50a5ce8eb78

[caryclark, 2016-08-24 20:05:09]

Description was changed from

==========
add pathops debugging

Pathops has many points of failure, most of which
are triggered by extreme data generated by fuzzers.
It's difficult to figure out which failure point
was triggered when the operation gives up.

Add instrumentation so that the failure can
be debugged when the data is well-behaved.

Also, add a check that looks for a sequence of
coincident points on multiple edges that are out
of order when compared to each other.

TBR=reed@google.com
==========

to

==========
add pathops debugging

Pathops has many points of failure, most of which
are triggered by extreme data generated by fuzzers.
It's difficult to figure out which failure point
was triggered when the operation gives up.

Add instrumentation so that the failure can
be debugged when the data is well-behaved.

Also, add a check that looks for a sequence of
coincident points on multiple edges that are out
of order when compared to each other.

TBR=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2274803003
==========

[caryclark, 2016-08-24 20:06:31]

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

[commit-bot: I haz the power, 2016-08-24 20:06:40]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-24 20:44:38]

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

[commit-bot: I haz the power, 2016-08-24 20:44:39]

Dry run: This issue passed the CQ dry run.

[caryclark, 2016-08-25 12:20:10]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2016-08-25 12:20:20]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-25 12:21:16]

Description was changed from

==========
add pathops debugging

Pathops has many points of failure, most of which
are triggered by extreme data generated by fuzzers.
It's difficult to figure out which failure point
was triggered when the operation gives up.

Add instrumentation so that the failure can
be debugged when the data is well-behaved.

Also, add a check that looks for a sequence of
coincident points on multiple edges that are out
of order when compared to each other.

TBR=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2274803003
==========

to

==========
add pathops debugging

Pathops has many points of failure, most of which
are triggered by extreme data generated by fuzzers.
It's difficult to figure out which failure point
was triggered when the operation gives up.

Add instrumentation so that the failure can
be debugged when the data is well-behaved.

Also, add a check that looks for a sequence of
coincident points on multiple edges that are out
of order when compared to each other.

TBR=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2274803003

Committed:
https://skia.googlesource.com/skia/+/025b11ecde8733d9b3eee54e132cc50a5ce8eb78
==========

[commit-bot: I haz the power, 2016-08-25 12:21:20]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/025b11ecde8733d9b3eee54e132cc50a5ce8eb78