fix winding for path ops builder

The path ops builder code needs to determine the winding of each contour added, and reverse windings if the contours are nested in other contours.

Cheap (one contour) paths can be evaluated and reversed as needed with a minimum of checking, but multi-contour paths invoke the regular path ops machinery to determine who is contained by whom.

More tests need to be added to verify that all corner cases are considered, but this fixes the cases in the bug thus far.


R=fmalita@chromium.org
TBR=reed@google.com
BUG=skia:3838
Committed: https://skia.googlesource.com/skia/+/5b5ddd73b4baf22752924bf20d097e96236c36f8

[caryclark, 2015-05-15 20:21:38]

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

[commit-bot: I haz the power, 2015-05-15 20:21:57]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1129193006/10011

[commit-bot: I haz the power, 2015-05-15 20:25:38]

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

[commit-bot: I haz the power, 2015-05-15 20:25:39]

Dry run: Try jobs failed on following builders:
  Build-Win-MSVC-x86-Debug-Trybot on client.skia.compile (JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Win-MSVC-x86-D...)
  Build-Win-MSVC-x86_64-Debug-Trybot on client.skia.compile (JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Win-MSVC-x86_6...)

[caryclark, 2015-05-15 20:38:21]

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

[commit-bot: I haz the power, 2015-05-15 20:38:39]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1129193006/30001

[commit-bot: I haz the power, 2015-05-16 22:46:52]

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

[commit-bot: I haz the power, 2015-05-16 22:46:54]

Dry run: This issue passed the CQ dry run.

[caryclark, 2015-05-18 12:06:13]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2015-05-18 12:06:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1129193006/30001

[commit-bot: I haz the power, 2015-05-18 12:13:03]

Committed patchset #3 (id:30001) as
https://skia.googlesource.com/skia/+/5b5ddd73b4baf22752924bf20d097e96236c36f8