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..18fec6a0f169afc51c450751f47f65b96afb90c8 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 +62,24 @@ test(() => {
   assert_dom_point_equals(point, [10, 20, 30, 40]);
 }, 'DOMPoint setter');
 
-</script>
+test(() => {
+  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 create a DOMPoint');
+
+test(() => {
+  var point = DOMPoint.fromPoint();
+  assert_dom_point_equals(point, [0, 0, 0, 1]);
+}, 'DOMPoint.fromPoint() should create a DOMPoint');
+
+test(() => {
+  var point1 = DOMPoint.fromPoint();
+  var point2 = DOMPoint.fromPoint();
+  assert_false(point1 == point2);
+  assert_true(point1.x == point2.x);
+  assert_true(point1.y == point2.y);
+  assert_true(point1.z == point2.z);
+  assert_true(point1.w == point2.w);
+}, 'DOMPoint.fromPoint() should create a new DOMPoint');
+
+</script>