[GeometryInterface] Implement DOMQuad and DOMQuadInit.

third_party/WebKit/Source/core/dom/DOMQuad.idl

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://drafts.fxtf.org/geometry/#domquad
+
+[
+ Constructor(optional DOMPointInit p1, optional DOMPointInit p2,
+                  optional DOMPointInit p3, optional DOMPointInit p4),
+ // TODO(hs1217.lee): Exposed=(Window,Worker)
+ RuntimeEnabled=GeometryInterfaces
+]
+interface DOMQuad {
+    // TODO(hs1217.lee): [NewObject] static DOMQuad fromRect(optional DOMRectInit other);
+    // TODO(hs1217.lee): [NewObject] static DOMQuad fromQuad(optional DOMQuadInit other);
+
+    [SameObject] readonly attribute DOMPoint p1;
+    [SameObject] readonly attribute DOMPoint p2;
+    [SameObject] readonly attribute DOMPoint p3;
+    [SameObject] readonly attribute DOMPoint p4;
+    // TODO(hs1217.lee): [NewObject] DOMRect getBounds();
+
+    // TODO(hs1217.lee): serializer = { attribute };
+};