Added built-in noVNC support.

public/novnc/core/util/polyfill.js

@@ -0,0 +1,54 @@
+/*
+ * noVNC: HTML5 VNC client
+ * Copyright (C) 2018 The noVNC Authors
+ * Licensed under MPL 2.0 or any later version (see LICENSE.txt)
+ */
+
+/* Polyfills to provide new APIs in old browsers */
+
+/* Object.assign() (taken from MDN) */
+if (typeof Object.assign != 'function') {
+    // Must be writable: true, enumerable: false, configurable: true
+    Object.defineProperty(Object, "assign", {
+        value: function assign(target, varArgs) { // .length of function is 2
+            'use strict';
+            if (target == null) { // TypeError if undefined or null
+                throw new TypeError('Cannot convert undefined or null to object');
+            }
+
+            const to = Object(target);
+
+            for (let index = 1; index < arguments.length; index++) {
+                const nextSource = arguments[index];
+
+                if (nextSource != null) { // Skip over if undefined or null
+                    for (let nextKey in nextSource) {
+                        // Avoid bugs when hasOwnProperty is shadowed
+                        if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
+                            to[nextKey] = nextSource[nextKey];
+                        }
+                    }
+                }
+            }
+            return to;
+        },
+        writable: true,
+        configurable: true
+    });
+}
+
+/* CustomEvent constructor (taken from MDN) */
+(() => {
+    function CustomEvent(event, params) {
+        params = params || { bubbles: false, cancelable: false, detail: undefined };
+        const evt = document.createEvent( 'CustomEvent' );
+        evt.initCustomEvent( event, params.bubbles, params.cancelable, params.detail );
+        return evt;
+    }
+
+    CustomEvent.prototype = window.Event.prototype;
+
+    if (typeof window.CustomEvent !== "function") {
+        window.CustomEvent = CustomEvent;
+    }
+})();