round and bevel hairline rects show the same as miter hairline rects

round and bevel hairline rects show the same as miter hairline rects

So round and bevel hairline rects can generate the vertices and indices the same as miter rects do. The original code behaves the same as bevel rects for round and bevel hairline rects.

This small CL can save (vertices and indices) buffer memory as well as improve performance (draw less triangles).

gm cases show no difference after this CL is applied.

BUG=skia:
R=robertphillips@google.com

Author: yunchao.he@intel.com

Review URL: https://codereview.chromium.org/417113002