shape ops work in progress

first 100,000 random cubic/cubic intersections working

git-svn-id: http://skia.googlecode.com/svn/trunk@7380 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/Intersection/CubeRoot.cpp b/experimental/Intersection/CubeRoot.cpp
index 82d2732..5f785a0 100644
--- a/experimental/Intersection/CubeRoot.cpp
+++ b/experimental/Intersection/CubeRoot.cpp
@@ -374,7 +374,7 @@
 #endif
 
 double cube_root(double x) {
-    if (approximately_zero(x)) {
+    if (approximately_zero_cubed(x)) {
         return 0;
     }
     double result = halley_cbrt3d(fabs(x));