Fix step timing outside range [0,1]

cc/animation/timing_function.cc

Index: cc/animation/timing_function.cc
diff --git a/cc/animation/timing_function.cc b/cc/animation/timing_function.cc
index b7308bb31c9564fa588a296172a640a631ac70e0..d0d55ad54fa75f6357fc3318229048a7d49e54f0 100644
--- a/cc/animation/timing_function.cc
+++ b/cc/animation/timing_function.cc
@@ -109,8 +109,12 @@ float StepsTimingFunction::Velocity(double x) const {
 
 double StepsTimingFunction::GetPreciseValue(double t) const {
   const double steps = static_cast<double>(steps_);
-  return MathUtil::ClampToRange(
-      std::floor((steps * t) + GetStepsStartOffset()) / steps, 0.0, 1.0);
+  double current_step = std::floor((steps * t) + GetStepsStartOffset());
+  if (t >= 0 && current_step < 0)
+    current_step = 0;
+  if (t <= 1 && current_step > steps)
+    current_step = steps;
+  return current_step / steps;
 }
 
 float StepsTimingFunction::GetStepsStartOffset() const {