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

cc/blink/web_filter_animation_curve_impl.cc

Index: cc/blink/web_filter_animation_curve_impl.cc
diff --git a/cc/blink/web_filter_animation_curve_impl.cc b/cc/blink/web_filter_animation_curve_impl.cc
index 9206dc735252989bdfcc26c884d9e6cf794235e5..79ffdfae1643f8c421486796e00b392a99a470ad 100644
--- a/cc/blink/web_filter_animation_curve_impl.cc
+++ b/cc/blink/web_filter_animation_curve_impl.cc
@@ -60,18 +60,30 @@ void WebFilterAnimationCurveImpl::add(const WebFilterKeyframe& keyframe,
       cc::StepsTimingFunction::Create(steps, steps_start_offset)));
 }
 
-void WebFilterAnimationCurveImpl::setTimingFunction(TimingFunctionType type) {
+void WebFilterAnimationCurveImpl::setLinearTimingFunction() {
+  curve_->SetTimingFunction(nullptr);
+}
+
+void WebFilterAnimationCurveImpl::setCubicBezierTimingFunction(
+    TimingFunctionType type) {
   curve_->SetTimingFunction(CreateTimingFunction(type));
 }
 
-void WebFilterAnimationCurveImpl::setTimingFunction(double x1,
-                                                    double y1,
-                                                    double x2,
-                                                    double y2) {
+void WebFilterAnimationCurveImpl::setCubicBezierTimingFunction(double x1,
+                                                               double y1,
+                                                               double x2,
+                                                               double y2) {
   curve_->SetTimingFunction(
       cc::CubicBezierTimingFunction::Create(x1, y1, x2, y2).Pass());
 }
 
+void WebFilterAnimationCurveImpl::setStepsTimingFunction(
+    int number_of_steps,
+    float steps_start_offset) {
+  curve_->SetTimingFunction(cc::StepsTimingFunction::Create(
+                                number_of_steps, steps_start_offset).Pass());
+}
+
 scoped_ptr<cc::AnimationCurve>
 WebFilterAnimationCurveImpl::CloneToAnimationCurve() const {
   return curve_->Clone();