Remove unused GraphicsLayerAnimation

Source/core/platform/animation/TimingFunction.h

Index: Source/core/platform/animation/TimingFunction.h
diff --git a/Source/core/platform/animation/TimingFunction.h b/Source/core/platform/animation/TimingFunction.h
index ae4c5afaebf16187065016d7fdf7d884c3a94b0f..e3446f7ad65f3e6acffd07235bbdfac535907929 100644
--- a/Source/core/platform/animation/TimingFunction.h
+++ b/Source/core/platform/animation/TimingFunction.h
@@ -134,13 +134,7 @@ public:
     double y2() const { return m_y2; }
     
     TimingFunctionPreset timingFunctionPreset() const { return m_timingFunctionPreset; }
-    
-    static const CubicBezierTimingFunction* defaultTimingFunction()
-    {
-        static const CubicBezierTimingFunction* dtf = create().leakRef();
-        return dtf;
-    }
-    
+
 private:
     explicit CubicBezierTimingFunction(TimingFunctionPreset preset = Ease, double x1 = 0.25, double y1 = 0.1, double x2 = 0.25, double y2 = 1.0)
         : TimingFunction(CubicBezierFunction)