Limitation of iceweasel rendering.

 * circle 1078 nodes, and 2 polylines have each 538 nodes.
 * Specification
   - Debian GNU/Linux Sid as VirtualBox Guest with SATA SSD
   - CPU core 7 (2.7 GHz Intel Core i7)
   - Memory 10GB
   - Iceweasel 24.5.0

Signed-off-by: Kouhei Maeda <mkouhei@palmtb.net>