Add support for inverse transform animations.

ui/compositor/transform_animation_curve_adapter.h

Index: ui/compositor/transform_animation_curve_adapter.h
diff --git a/ui/compositor/transform_animation_curve_adapter.h b/ui/compositor/transform_animation_curve_adapter.h
index 7b6bdcea52b33fa073faad3f3ddce2f76ab5ffd9..a2f8726c70acb32a9483cabcd75deafb5750baf4 100644
--- a/ui/compositor/transform_animation_curve_adapter.h
+++ b/ui/compositor/transform_animation_curve_adapter.h
@@ -36,6 +36,25 @@ class TransformAnimationCurveAdapter :public cc::TransformAnimationCurve {
   base::TimeDelta duration_;
 };
 
+class CounterTransformCurveAdapter :public cc::TransformAnimationCurve {
+ public:
+  CounterTransformCurveAdapter(TransformAnimationCurveAdapter parent_curve,
+                               gfx::Transform initial_value,
+                               base::TimeDelta duration);
+
+  virtual ~CounterTransformCurveAdapter();
+
+  virtual double Duration() const OVERRIDE;
+  virtual scoped_ptr<AnimationCurve> Clone() const OVERRIDE;
+  virtual gfx::Transform GetValue(double t) const OVERRIDE;
+
+ private:
+  TransformAnimationCurveAdapter parent_curve_;
+  gfx::Transform initial_value_;
+  gfx::Transform effective_initial_value_;
+  base::TimeDelta duration_;
+};
+
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_TRANSFORM_ANIMATION_CURVE_ADAPTER_H_