CC: Allow per-curve timing functions to be steps timing functions

cc/blink/web_float_animation_curve_impl.cc

Index: cc/blink/web_float_animation_curve_impl.cc
diff --git a/cc/blink/web_float_animation_curve_impl.cc b/cc/blink/web_float_animation_curve_impl.cc
index ca5b5d0446394bda8ff805a3f53a4d080a3c0e21..4340ae8bdabbeed29f9f2ea8d210fd423b5107cf 100644
--- a/cc/blink/web_float_animation_curve_impl.cc
+++ b/cc/blink/web_float_animation_curve_impl.cc
@@ -54,18 +54,30 @@ void WebFloatAnimationCurveImpl::add(const WebFloatKeyframe& keyframe,
       cc::StepsTimingFunction::Create(steps, steps_start_offset)));
 }
 
-void WebFloatAnimationCurveImpl::setTimingFunction(TimingFunctionType type) {
+void WebFloatAnimationCurveImpl::setLinearTimingFunction() {
+  curve_->SetTimingFunction(nullptr);
+}
+
+void WebFloatAnimationCurveImpl::setCubicBezierTimingFunction(
+    TimingFunctionType type) {
   curve_->SetTimingFunction(CreateTimingFunction(type));
 }
 
-void WebFloatAnimationCurveImpl::setTimingFunction(double x1,
-                                                   double y1,
-                                                   double x2,
-                                                   double y2) {
+void WebFloatAnimationCurveImpl::setCubicBezierTimingFunction(double x1,
+                                                              double y1,
+                                                              double x2,
+                                                              double y2) {
   curve_->SetTimingFunction(
       cc::CubicBezierTimingFunction::Create(x1, y1, x2, y2).Pass());
 }
 
+void WebFloatAnimationCurveImpl::setStepsTimingFunction(
+    int number_of_steps,
+    float steps_start_offset) {
+  curve_->SetTimingFunction(cc::StepsTimingFunction::Create(
+                                number_of_steps, steps_start_offset).Pass());
+}
+
 float WebFloatAnimationCurveImpl::getValue(double time) const {
   return curve_->GetValue(base::TimeDelta::FromSecondsD(time));
 }