Do not clamp y values on internal knots of timing function bezier curves

cc/animation/timing_function.h

Index: cc/animation/timing_function.h
diff --git a/cc/animation/timing_function.h b/cc/animation/timing_function.h
index b1080e6cf1b1629edf9d52c210f009bbc9007b4a..3aa2f253d81fdbb933e1ca6eb34454f0c8088b23 100644
--- a/cc/animation/timing_function.h
+++ b/cc/animation/timing_function.h
@@ -39,10 +39,10 @@ class CC_EXPORT CubicBezierTimingFunction : public TimingFunction {
  protected:
   CubicBezierTimingFunction(double x1, double y1, double x2, double y2);
 
-  SkScalar x1_;
-  SkScalar y1_;
-  SkScalar x2_;
-  SkScalar y2_;
+  double x1_;
+  double y1_;
+  double x2_;
+  double y2_;
 
  private:
   DISALLOW_ASSIGN(CubicBezierTimingFunction);