Add support for bounds animations

cc/animation/animation_curve.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_ANIMATION_CURVE_H_
 #define CC_ANIMATION_ANIMATION_CURVE_H_
 
 #include <memory>
 
 #include "base/time/time.h"
 #include "cc/animation/animation_export.h"
 #include "cc/base/filter_operations.h"
+#include "ui/gfx/geometry/size_f.h"
 #include "ui/gfx/transform.h"
 
 namespace gfx {
 class BoxF;
 }
 
 namespace cc {
 
 class ColorAnimationCurve;
 class FilterAnimationCurve;
 class FloatAnimationCurve;
 class ScrollOffsetAnimationCurve;
+class SizeAnimationCurve;
 class TransformAnimationCurve;
 
 // An animation curve is a function that returns a value given a time.
 class CC_ANIMATION_EXPORT AnimationCurve {
  public:
-  enum CurveType { COLOR, FLOAT, TRANSFORM, FILTER, SCROLL_OFFSET };
+  enum CurveType { COLOR, FLOAT, TRANSFORM, FILTER, SCROLL_OFFSET, SIZE };
 
   virtual ~AnimationCurve() {}
 
   virtual base::TimeDelta Duration() const = 0;
   virtual CurveType Type() const = 0;
   virtual std::unique_ptr<AnimationCurve> Clone() const = 0;
 
   const ColorAnimationCurve* ToColorAnimationCurve() const;
   const FloatAnimationCurve* ToFloatAnimationCurve() const;
   const TransformAnimationCurve* ToTransformAnimationCurve() const;
   const FilterAnimationCurve* ToFilterAnimationCurve() const;
   const ScrollOffsetAnimationCurve* ToScrollOffsetAnimationCurve() const;
+  const SizeAnimationCurve* ToSizeAnimationCurve() const;
 
   ScrollOffsetAnimationCurve* ToScrollOffsetAnimationCurve();
 };
 
 class CC_ANIMATION_EXPORT ColorAnimationCurve : public AnimationCurve {
  public:
   ~ColorAnimationCurve() override {}
 
   virtual SkColor GetValue(base::TimeDelta t) const = 0;
 
@@ skipping 49 matching lines @@
  public:
   ~FilterAnimationCurve() override {}
 
   virtual FilterOperations GetValue(base::TimeDelta t) const = 0;
   virtual bool HasFilterThatMovesPixels() const = 0;
 
   // Partial Animation implementation.
   CurveType Type() const override;
 };
 
+class CC_ANIMATION_EXPORT SizeAnimationCurve : public AnimationCurve {
+ public:
+  ~SizeAnimationCurve() override {}
+
+  virtual gfx::SizeF GetValue(base::TimeDelta t) const = 0;
+
+  // Partial Animation implementation.
+  CurveType Type() const override;
+};
+
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ANIMATION_CURVE_H_