Layout support for new circle shape syntax

LayoutTests/css3/masking/clip-path-animation.html

Index: LayoutTests/css3/masking/clip-path-animation.html
diff --git a/LayoutTests/css3/masking/clip-path-animation.html b/LayoutTests/css3/masking/clip-path-animation.html
index 1a512ea1e9a70d01bfac1571e408ac0168ce50d9..8cab6192515a53dab73150b6b63742c314016436 100644
--- a/LayoutTests/css3/masking/clip-path-animation.html
+++ b/LayoutTests/css3/masking/clip-path-animation.html
@@ -34,8 +34,8 @@
     }
 
     @-webkit-keyframes circle-anim {
-        from { -webkit-clip-path: circle(50%, 50%, 50%); }
-        to   { -webkit-clip-path: circle(20%, 20%, 20%); }
+        from { -webkit-clip-path: circle(50% at 50% 50%); }
+        to   { -webkit-clip-path: circle(20% at 20% 20%); }
     }
 
     @-webkit-keyframes ellipse-anim {
@@ -54,7 +54,7 @@
     const expectedValues = [
       // [time, element-id, property, expected-value, tolerance]
       [1, "rectangle-box", "webkitClipPath", "rectangle(10%, 10%, 80%, 80%, 0px, 0px)", 0.05],
-      [1, "circle-box", "webkitClipPath", "circle(35%, 35%, 35%)", 0.05],
+      [1, "circle-box", "webkitClipPath", "circle(35% at 35% 35%)", 0.05],
       [1, "ellipse-box", "webkitClipPath", "ellipse(35%, 35%, 35%, 30%)", 0.05],
       [1, "polygon-box", "webkitClipPath", "polygon(nonzero, 10% 10%, 90% 10%, 90% 90%, 10% 90%)", 0.05],
     ];