[Fixed Position] Add proxy object

Add proxy object to represent the selection of the fixed position
view itself, WTD-879.

platform/features/layout/src/FixedProxy.js

@@ -0,0 +1,26 @@
+/*global define*/
+
+define(
+    [],
+    function () {
+        "use strict";
+
+        /**
+         * Proxy for configuring a fixed position view via the toolbar.
+         * @constructor
+         * @param configuration the view configuration object
+         */
+        function FixedProxy(configuration) {
+            return {
+                /**
+                 * Add a new visual element to this view.
+                 */
+                add: function (type) {
+                    window.alert("Placeholder. Should add a " + type + ".");
+                }
+            };
+        }
+
+        return FixedProxy;
+    }
+);