shape ops work in progress

git-svn-id: http://skia.googlecode.com/svn/trunk@6223 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/Intersection/QuarticRoot.cpp b/experimental/Intersection/QuarticRoot.cpp
index f16c332..7a95b24 100644
--- a/experimental/Intersection/QuarticRoot.cpp
+++ b/experimental/Intersection/QuarticRoot.cpp
@@ -155,7 +155,7 @@
     double r;
     double* roots = s;
 
-    if (R2MinusQ3 > -FLT_EPSILON / 10 && R2MinusQ3 < FLT_EPSILON / 10 ) {
+    if (approximately_zero_squared(R2MinusQ3)) {
         if (approximately_zero(R)) {/* one triple solution */
             *roots++ = -adiv3;
         } else { /* one single and one double solution */
@@ -216,7 +216,7 @@
         s[num++] = 0;
         return num;
     }
-    if (approximately_zero(A + B + C + D + E)) { // 1 is one root
+    if (approximately_zero_squared(A + B + C + D + E)) { // 1 is one root
         num = cubicRootsX(A, A + B, -(D + E), -E, s); // note that -C==A+B+D+E
         for (i = 0; i < num; ++i) {
             if (approximately_equal(s[i], 1)) {