Add intersections for path ops

src/pathops/SkQuarticRoot.h

Index: src/pathops/SkQuarticRoot.h
===================================================================
--- src/pathops/SkQuarticRoot.h	(revision 0)
+++ src/pathops/SkQuarticRoot.h	(revision 0)
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkDQuarticRoot_DEFINED
+#define SkDQuarticRoot_DEFINED
+
+int SkReducedQuarticRoots(const double t4, const double t3, const double t2, const double t1,
+        const double t0, const bool oneHint, double s[4]);
+
+int SkQuarticRootsReal(int firstCubicRoot, const double A, const double B, const double C,
+        const double D, const double E, double s[4]);
+
+#endif