fix path op builder

fix path op builder

The rewrite of path ops caused the inner contour direction to be reversed.
This exposed an existing bug in path ops builder, namely that the implicit
winding of the internal sum path could hide inner contours if they ended
up in the wrong direction.

Setting the sum path's fill type to even-odd ensures that the inner
contours aren't discarded.

R=fmalita@chromium.org
BUG=skia:3838
Committed: https://skia.googlesource.com/skia/+/fba9da78acf8853f0074d0518411bafc827f3771

[caryclark, 2015-05-14 18:38:16]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2015-05-14 18:38:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1126193004/1

[commit-bot: I haz the power, 2015-05-14 18:38:42]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-05-15 00:38 UTC

[f(malita), 2015-05-14 19:14:22]

lgtm

[commit-bot: I haz the power, 2015-05-14 21:18:18]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/fba9da78acf8853f0074d0518411bafc827f3771