UI GFX Geometry: Make UnitBezier a wrapper for gfx::CubicBezier

ui/gfx/geometry/cubic_bezier_unittest.cc

Index: ui/gfx/geometry/cubic_bezier_unittest.cc
diff --git a/ui/gfx/geometry/cubic_bezier_unittest.cc b/ui/gfx/geometry/cubic_bezier_unittest.cc
index 9ade0daf42fca709bf8acaeb99e1f658ebbfb83c..18ecebbd2a6d9b59d6ed6ba3861b2f94ffaa3628 100644
--- a/ui/gfx/geometry/cubic_bezier_unittest.cc
+++ b/ui/gfx/geometry/cubic_bezier_unittest.cc
@@ -35,6 +35,15 @@ TEST(CubicBezierTest, Basic) {
   EXPECT_NEAR(function.Solve(0.9), 0.96021, epsilon);
   EXPECT_NEAR(function.Solve(0.95), 0.98863, epsilon);
   EXPECT_NEAR(function.Solve(1), 1, epsilon);
+
+  CubicBezier basicUse(0.5, 1.0, 0.5, 1.0);
+  EXPECT_EQ(0.875, basicUse.Solve(0.5));
+
+  CubicBezier overshoot(0.5, 2.0, 0.5, 2.0);
+  EXPECT_EQ(1.625, overshoot.Solve(0.5));
+
+  CubicBezier undershoot(0.5, -1.0, 0.5, -1.0);
+  EXPECT_EQ(-0.625, undershoot.Solve(0.5));
 }
 
 // Tests that solving the bezier works with knots with y not in (0, 1).
@@ -169,6 +178,14 @@ TEST(CubicBezierTest, InputOutOfRange) {
   EXPECT_EQ(-2.0, simple.Solve(-1.0));
   EXPECT_EQ(1.0, simple.Solve(2.0));
 
+  CubicBezier atEdgeOfRange(0.5, 1.0, 0.5, 1.0);
+  EXPECT_EQ(0.0, atEdgeOfRange.Solve(0.0));
+  EXPECT_EQ(1.0, atEdgeOfRange.Solve(1.0));
+
+  CubicBezier largeEpsilon(0.5, 1.0, 0.5, 1.0);
+  EXPECT_EQ(-2.0, largeEpsilon.SolveWithEpsilon(-1.0, 1.0));
+  EXPECT_EQ(1.0, largeEpsilon.SolveWithEpsilon(2.0, 1.0));
+
   CubicBezier coincidentEndpoints(0.0, 0.0, 1.0, 1.0);
   EXPECT_EQ(-1.0, coincidentEndpoints.Solve(-1.0));
   EXPECT_EQ(2.0, coincidentEndpoints.Solve(2.0));