Change tessellator sweep direction to depend on path aspect ratio.

Change tessellator sweep direction to depend on path aspect ratio.

The tessellating path renderer uses several sweep-line algorithms,
whose sweep direction can be either in X or Y.

It is currently set to in-X at compile time, but a better approach is to
make it runtime-configurable, and use the path aspect ratio as
a heuristic to determine the optimal sweep direction.

BUG=skia:3725
Committed: https://skia.googlesource.com/skia/+/6bd5137e11071116fe279e2f26264f01baeff1aa

[Stephen White, 2015-04-14 21:51:29]

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

[Stephen White, 2015-04-14 21:51:54]

The CQ bit was checked by senorblanco@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-04-14 21:52:07]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1089073002/60001

[Stephen White, 2015-04-14 21:52:08]

Greg: PTAL. Thanks!

[commit-bot: I haz the power, 2015-04-14 21:58:04]

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

[commit-bot: I haz the power, 2015-04-14 21:58:05]

This issue passed the CQ dry run.

[Stephen White, 2015-04-14 22:02:02]

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

[Stephen White, 2015-04-14 22:02:12]

Brian || Greg: PTAL. Thanks! :)

[bsalomon, 2015-04-15 13:32:01]

lgtm

[Stephen White, 2015-04-15 13:48:57]

The CQ bit was checked by senorblanco@chromium.org

[commit-bot: I haz the power, 2015-04-15 13:49:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1089073002/60001

[commit-bot: I haz the power, 2015-04-15 14:32:30]

Committed patchset #4 (id:60001) as
https://skia.googlesource.com/skia/+/6bd5137e11071116fe279e2f26264f01baeff1aa