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

cc/blink/web_transform_animation_curve_impl.h

Index: cc/blink/web_transform_animation_curve_impl.h
diff --git a/cc/blink/web_transform_animation_curve_impl.h b/cc/blink/web_transform_animation_curve_impl.h
index 6dc64b57bf9ed812b3037686a2bd1e94caa4c628..81ed6073fa7bff8c2783cd12ad5434992cfc08a2 100644
--- a/cc/blink/web_transform_animation_curve_impl.h
+++ b/cc/blink/web_transform_animation_curve_impl.h
@@ -41,9 +41,14 @@ class WebTransformAnimationCurveImpl
   virtual void add(const blink::WebTransformKeyframe& keyframe,
                    int steps,
                    float stepsStartOffset);
-
-  virtual void setTimingFunction(TimingFunctionType type);
-  virtual void setTimingFunction(double x1, double y1, double x2, double y2);
+  virtual void setLinearTimingFunction();
+  virtual void setCubicBezierTimingFunction(TimingFunctionType);
+  virtual void setCubicBezierTimingFunction(double x1,
+                                            double y1,
+                                            double x2,
+                                            double y2);
+  virtual void setStepsTimingFunction(int number_of_steps,
+                                      float steps_start_offset);
 
   scoped_ptr<cc::AnimationCurve> CloneToAnimationCurve() const;