Geometry: Reimplement DOMPoint using V8 extras.

third_party/WebKit/Source/modules/geometry/DOMPointReadOnly.js

+// Copyright 2016 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.
+
+(function(global, binding, v8) {
+  'use strict';
+
+  const defineProperty = global.Object.defineProperty;
+
+  class DOMPointReadOnly {
+    constructor(x = 0, y = 0, z = 0, w = 1) {
+      defineProperty(this, 'x', {

[domenic, 2016/02/18 19:04:41]

While I personally prefer this design, the spec mandates the use of getters and
setters (that's what Web IDL's "attributes" are). So you'll instead need to
store these values in private symbols, and add things like `get x() { return
this[xSymbol]; }` to the class definition.

[zino, 2016/02/22 09:51:01]

Done.

+        value: x,
+        configurable: true,
+        enumerable: true,
+        writable: false
+      });
+
+      defineProperty(this, 'y', {
+        value: y,
+        configurable: true,
+        enumerable: true,
+        writable: false
+      });
+
+      defineProperty(this, 'z', {
+        value: z,
+        configurable: true,
+        enumerable: true,
+        writable: false
+      });
+
+      defineProperty(this, 'w', {
+        value: w,
+        configurable: true,
+        enumerable: true,
+        writable: false
+      });
+    }
+
+    static fromPoint(init) {
+      return new DOMPointReadOnly(init.x, init.y, init.z, init.w);
+    }
+  }
+
+  binding.createDOMPointReadOnly = DOMPointReadOnly.fromPoint;

[domenic, 2016/02/18 19:04:41]

An option here would be to instead do `binding.createDOMPointReadOnly = (x, y,
z, w) => new DOMPointReadOnly(x, y, z, w)`. That would save you from doing the
V8ObjectBuilder stuff and avoid a level of indirection. Might even give a slight
perf boost.

[zino, 2016/02/22 09:51:01]

Done.

+
+  defineProperty(global, 'DOMPointReadOnly', {
+    value: DOMPointReadOnly,
+    configurable: true,
+    enumerable: false,
+    writable: true
+  });
+});