Blink Compositor Animation: Make Animation and Curve methods non-virtual.

cc/animation/timing_function.h

 // Copyright 2012 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.
 
 #ifndef CC_ANIMATION_TIMING_FUNCTION_H_
 #define CC_ANIMATION_TIMING_FUNCTION_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "ui/gfx/geometry/cubic_bezier.h"
 
 namespace cc {
 
 // See http://www.w3.org/TR/css3-transitions/.
 class CC_EXPORT TimingFunction {
  public:
   virtual ~TimingFunction();
 
+  // Note that LINEAR is a nullptr TimingFunction (for now).
+  enum class Type { LINEAR, CUBIC_BEZIER, STEPS };
+
+  virtual Type GetType() const = 0;
   virtual float GetValue(double t) const = 0;
   virtual float Velocity(double time) const = 0;
   // The smallest and largest values returned by GetValue for inputs in [0, 1].
   virtual void Range(float* min, float* max) const = 0;
   virtual std::unique_ptr<TimingFunction> Clone() const = 0;
 
  protected:
   TimingFunction();
 
  private:
   DISALLOW_ASSIGN(TimingFunction);
 };
 
 class CC_EXPORT CubicBezierTimingFunction : public TimingFunction {
  public:
   enum class EaseType { EASE, EASE_IN, EASE_OUT, EASE_IN_OUT, CUSTOM };
 
   static std::unique_ptr<TimingFunction> CreatePreset(EaseType ease_type);
   static std::unique_ptr<CubicBezierTimingFunction> Create(double x1,
                                                            double y1,
                                                            double x2,
                                                            double y2);
   ~CubicBezierTimingFunction() override;
 
   // TimingFunction implementation.
+  Type GetType() const override;
   float GetValue(double time) const override;
   float Velocity(double time) const override;
   void Range(float* min, float* max) const override;
   std::unique_ptr<TimingFunction> Clone() const override;
 
+  EaseType ease_type() const { return ease_type_; }
+
  protected:
-  CubicBezierTimingFunction(double x1, double y1, double x2, double y2);
+  CubicBezierTimingFunction(EaseType ease_type,
+                            double x1,
+                            double y1,
+                            double x2,
+                            double y2);
 
   gfx::CubicBezier bezier_;
+  EaseType ease_type_;
 
  private:
   DISALLOW_ASSIGN(CubicBezierTimingFunction);
 };
 
 class CC_EXPORT EaseTimingFunction {
  public:
   static std::unique_ptr<TimingFunction> Create();
 
  private:
@@ skipping 27 matching lines @@
 class CC_EXPORT StepsTimingFunction : public TimingFunction {
  public:
   // Web Animations specification, 3.12.4. Timing in discrete steps.
   enum class StepPosition { START, MIDDLE, END };
 
   static std::unique_ptr<StepsTimingFunction> Create(
       int steps,
       StepPosition step_position);
   ~StepsTimingFunction() override;
 
+  // TimingFunction implementation.
+  Type GetType() const override;
   float GetValue(double t) const override;
   std::unique_ptr<TimingFunction> Clone() const override;
-
   void Range(float* min, float* max) const override;
   float Velocity(double time) const override;
 
  protected:
   StepsTimingFunction(int steps, StepPosition step_position);
 
  private:
   int steps_;
   float steps_start_offset_;
 
   DISALLOW_ASSIGN(StepsTimingFunction);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_TIMING_FUNCTION_H_