Adding fromPoint to DOMPoint and DOMPointReadOnly interfaces following spec.

third_party/WebKit/LayoutTests/fast/dom/geometry-interfaces-dom-point.html

Index: third_party/WebKit/LayoutTests/fast/dom/geometry-interfaces-dom-point.html
diff --git a/third_party/WebKit/LayoutTests/fast/dom/geometry-interfaces-dom-point.html b/third_party/WebKit/LayoutTests/fast/dom/geometry-interfaces-dom-point.html
index 9c6fa14c5a512660b9e214d435f3dcdd50e658c1..2daa28654251d2fb3614f7627a18c5066d14eeef 100644
--- a/third_party/WebKit/LayoutTests/fast/dom/geometry-interfaces-dom-point.html
+++ b/third_party/WebKit/LayoutTests/fast/dom/geometry-interfaces-dom-point.html
@@ -62,4 +62,9 @@ test(() => {
   assert_dom_point_equals(point, [10, 20, 30, 40]);
 }, 'DOMPoint setter');
 
-</script>
+test(() => {

[zino, 2016/12/19 18:02:31]

I think you should add one more test to check whether the fromPoint() always
returns a new object.

[Byoungkwon Ko, 2016/12/19 18:59:42]

Done.

+  var point = DOMPoint.fromPoint({x: 1, y: 2, z: 3, w: 4});
+  assert_dom_point_equals(point, [1, 2, 3, 4]);
+}, 'DOMPoint.fromPoint({x: 1, y: 2, z: 3, w: 4}) should creat a DOMPoint');

[zino, 2016/12/19 18:02:31]

nit: should create

[Byoungkwon Ko, 2016/12/19 18:59:42]

Done.

+
+</script>