diff -r 000000000000 -r 6474c204b198 browser/devtools/webaudioeditor/panel.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/webaudioeditor/panel.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,66 @@
+/* -*- Mode: javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+const { Cc, Ci, Cu, Cr } = require("chrome");
+const EventEmitter = require("devtools/toolkit/event-emitter");
+const { WebAudioFront } = require("devtools/server/actors/webaudio");
+let Promise = Cu.import("resource://gre/modules/Promise.jsm", {}).Promise;
+
+function WebAudioEditorPanel (iframeWindow, toolbox) {
+  this.panelWin = iframeWindow;
+  this._toolbox = toolbox;
+  this._destroyer = null;
+
+  EventEmitter.decorate(this);
+}
+
+exports.WebAudioEditorPanel = WebAudioEditorPanel;
+
+WebAudioEditorPanel.prototype = {
+  open: function() {
+    let targetPromise;
+
+    // Local debugging needs to make the target remote.
+    if (!this.target.isRemote) {
+      targetPromise = this.target.makeRemote();
+    } else {
+      targetPromise = Promise.resolve(this.target);
+    }
+
+    return targetPromise
+      .then(() => {
+        this.panelWin.gToolbox = this._toolbox;
+        this.panelWin.gTarget = this.target;
+        this.panelWin.gFront = new WebAudioFront(this.target.client, this.target.form);
+        return this.panelWin.startupWebAudioEditor();
+      })
+      .then(() => {
+        this.isReady = true;
+        this.emit("ready");
+        return this;
+      })
+      .then(null, function onError(aReason) {
+        Cu.reportError("WebAudioEditorPanel open failed. " +
+                       aReason.error + ": " + aReason.message);
+      });
+  },
+
+  // DevToolPanel API
+
+  get target() this._toolbox.target,
+
+  destroy: function() {
+    // Make sure this panel is not already destroyed.
+    if (this._destroyer) {
+      return this._destroyer;
+    }
+
+    return this._destroyer = this.panelWin.shutdownWebAudioEditor().then(() => {
+      this.emit("destroyed");
+    });
+  }
+};