Add Color animation curves.

Implement animation curves for colors.

This is the first step towards accelerating background-color animations.

+ Add ColorValueBetween to gfx::Tween.
+ Add test/color_utils which gives EXPECT_COLOR_EQ to check SkColors and
  print in a sane format.
~ Fixed discrepancy between two methods of interpolating ints.
~ Factored out GetProgress into template function to simplify code in
  the implementations of GetValue(double), there was a lot of duplication
  there.

TESTED:
  Added tests for the new KeyframedColorAnimations and AnimatedColor classes. Added tests to tweening.

R=ajuma
BUG=290234

Review URL: https://codereview.chromium.org/25901002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230856 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 13 insertions, 1 deletions

diff --git a/cc/animation/animation_curve.h b/cc/animation/animation_curve.h
index f4cdb10..f84bb1a 100644
--- a/cc/animation/animation_curve.h
+++ b/cc/animation/animation_curve.h
@@ -16,6 +16,7 @@ class BoxF;
 
 namespace cc {
 
+class ColorAnimationCurve;
 class FilterAnimationCurve;
 class FloatAnimationCurve;
 class TransformAnimationCurve;
@@ -24,7 +25,7 @@ class TransformOperations;
 // An animation curve is a function that returns a value given a time.
 class CC_EXPORT AnimationCurve {
  public:
-  enum CurveType { Float, Transform, Filter };
+  enum CurveType { Color, Float, Transform, Filter };
 
   virtual ~AnimationCurve() {}
 
@@ -32,11 +33,22 @@ class CC_EXPORT AnimationCurve {
   virtual CurveType Type() const = 0;
   virtual scoped_ptr<AnimationCurve> Clone() const = 0;
 
+  const ColorAnimationCurve* ToColorAnimationCurve() const;
   const FloatAnimationCurve* ToFloatAnimationCurve() const;
   const TransformAnimationCurve* ToTransformAnimationCurve() const;
   const FilterAnimationCurve* ToFilterAnimationCurve() const;
 };
 
+class CC_EXPORT ColorAnimationCurve : public AnimationCurve {
+ public:
+  virtual ~ColorAnimationCurve() {}
+
+  virtual SkColor GetValue(double t) const = 0;
+
+  // Partial Animation implementation.
+  virtual CurveType Type() const OVERRIDE;
+};
+
 class CC_EXPORT FloatAnimationCurve : public AnimationCurve {
  public:
   virtual ~FloatAnimationCurve() {}