first support at shape ops support for quads

git-svn-id: http://skia.googlecode.com/svn/trunk@3520 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/Intersection/EdgeDemo.h b/experimental/Intersection/EdgeDemo.h
new file mode 100644
index 0000000..21c1563
--- /dev/null
+++ b/experimental/Intersection/EdgeDemo.h
@@ -0,0 +1,3 @@
+class SkCanvas;
+
+bool DrawEdgeDemo(SkCanvas* canvas, int step);