Check for degenerate edges in cubic->quad conversion called by convex path renderer.

Cubics that are nearly degenerate now make it down here via the convex path renderer. They used to get filtered out by the path iterator but that was problematic. We wound up producing NaN vertices.

BUG=2677
R=jvanverth@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/338633007
1 file changed