Don't add duplicate points when clipping

cc/base/math_util.h

Index: cc/base/math_util.h
diff --git a/cc/base/math_util.h b/cc/base/math_util.h
index 05014ee5c19dffd7abb676c8ba0a3f5e7e90753e..5d626d33d6a9e8d0616956e2df2663b7fd1891ab 100644
--- a/cc/base/math_util.h
+++ b/cc/base/math_util.h
@@ -310,6 +310,12 @@ class CC_EXPORT MathUtil {
   // Returns vector that y axis (0,1,0) transforms to under given transform.
   static gfx::Vector3dF GetYAxis(const gfx::Transform& transform);
 
+  static bool IsNearlyTheSameForTesting(float left, float right);
+  static bool IsNearlyTheSameForTesting(const gfx::PointF& l,
+                                        const gfx::PointF& r);
+  static bool IsNearlyTheSameForTesting(const gfx::Point3F& l,
+                                        const gfx::Point3F& r);
+
  private:
   template <typename T>
   static T RoundUpInternal(T n, T mul) {