add pathops tight bounds; conform path ops' gyp to unit tests

Implement path tight bounds using path ops machinery. This is not
as efficient as it could be; for instance, internally, it creates
a path ops structure more suited to intersection. If this shows
up as a performance bottleneck, it could be improved.

Fix path ops gyp files, which have fallen out of sync with other
tests.

R=mtklein@google.com, bsalomon@google.com
TBR=mtklein
BUG=skia:1712

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/348343002
6 files changed