Altered arcTo's canonical points to (usually) be convex

https://codereview.appspot.com/6709051/

This will require rebaselining of: degeneratesegments, shadertext & shadertext2



git-svn-id: http://skia.googlecode.com/svn/trunk@5997 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed