Add testing for Rectanizer-derived classes

This in preparation for expanding the Rectanizer API for removing rects and adding a new derived class

R=jvanverth@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/304313002

git-svn-id: http://skia.googlecode.com/svn/trunk@14972 2bbb7eff-a529-9590-31e7-b0007b416f81
9 files changed