Revert "Handle direction control in compositor Animations"

Source/core/animation/CompositorAnimations.h

Index: Source/core/animation/CompositorAnimations.h
diff --git a/Source/core/animation/CompositorAnimations.h b/Source/core/animation/CompositorAnimations.h
index 1d2a66406151bd970b95eab30e3629d9c5ba89fc..05aa23f36128b4046be798571924f89d622b1abb 100644
--- a/Source/core/animation/CompositorAnimations.h
+++ b/Source/core/animation/CompositorAnimations.h
@@ -40,6 +40,18 @@ namespace WebCore {
 
 class Element;
 
+// Given an input timing function between keyframe at 0 and keyframe at 1.0, we
+// need a timing function such that the behavior with the keyframes swapped is
+// equivalent to reversing time with the input timing function and keyframes.
+// This means flipping the timing function about x=0.5 and about y=0.5.
+// FIXME: Remove once the Compositor natively understands reversing time.
+class CompositorAnimationsTimingFunctionReverser {
+public:
+    static PassRefPtr<TimingFunction> reverse(const LinearTimingFunction* timefunc);
+    static PassRefPtr<TimingFunction> reverse(const CubicBezierTimingFunction* timefunc);
+    static PassRefPtr<TimingFunction> reverse(const TimingFunction* timefunc);
+};
+
 class CompositorAnimations {
 public:
     static CompositorAnimations* instance() { return instance(0); }