[WIP] Implement DOMPoint of geometry interface.

Source/core/dom/DOMPointReadOnly.js

+// Copyright 2014 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.
+
+'use strict';
+
+installClass('DOMPointReadOnly', function(global) {
+
+    var DOMPointReadOnlyPrototype = {};
+
+    DOMPointReadOnlyPrototype.initialize = function() {
+        this.m_x = 0;
+        this.m_y = 0;
+        this.m_z = 0;
+        this.m_w = 1;
+    };
+
+    Object.defineProperty(DOMPointReadOnlyPrototype, "x", {
+        get: function() { return this.m_x; },
+    });
+
+    Object.defineProperty(DOMPointReadOnlyPrototype, "y", {
+        get: function() { return this.m_y; },
+    });
+
+    Object.defineProperty(DOMPointReadOnlyPrototype, "z", {
+        get: function() { return this.m_z; },
+    });
+
+    Object.defineProperty(DOMPointReadOnlyPrototype, "w", {
+        get: function() { return this.m_w; },
+    });
+
+    return DOMPointReadOnlyPrototype;
+});