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

cc/blink/web_transform_animation_curve_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/blink/web_transform_animation_curve_impl.h"
 
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/timing_function.h"
 #include "cc/animation/transform_operations.h"
 #include "cc/blink/web_animation_curve_common.h"
@@ skipping 46 matching lines @@
                                          int steps,
                                          float steps_start_offset) {
   const cc::TransformOperations& transform_operations =
       static_cast<const WebTransformOperationsImpl&>(keyframe.value())
           .AsTransformOperations();
   curve_->AddKeyframe(cc::TransformKeyframe::Create(
       base::TimeDelta::FromSecondsD(keyframe.time()), transform_operations,
       cc::StepsTimingFunction::Create(steps, steps_start_offset)));
 }
 
-void WebTransformAnimationCurveImpl::setTimingFunction(
+void WebTransformAnimationCurveImpl::setLinearTimingFunction() {
+  curve_->SetTimingFunction(nullptr);
+}
+
+void WebTransformAnimationCurveImpl::setCubicBezierTimingFunction(
     TimingFunctionType type) {
   curve_->SetTimingFunction(CreateTimingFunction(type));
 }
 
-void WebTransformAnimationCurveImpl::setTimingFunction(double x1,
-                                                       double y1,
-                                                       double x2,
-                                                       double y2) {
+void WebTransformAnimationCurveImpl::setCubicBezierTimingFunction(double x1,
+                                                                  double y1,
+                                                                  double x2,
+                                                                  double y2) {
   curve_->SetTimingFunction(
       cc::CubicBezierTimingFunction::Create(x1, y1, x2, y2).Pass());
 }
 
+void WebTransformAnimationCurveImpl::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>
 WebTransformAnimationCurveImpl::CloneToAnimationCurve() const {
   return curve_->Clone();
 }
 
 }  // namespace cc_blink