diff -r 000000000000 -r 6474c204b198 addon-sdk/source/lib/sdk/content/utils.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/addon-sdk/source/lib/sdk/content/utils.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,82 @@
+/* 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';
+
+module.metadata = {
+  'stability': 'unstable'
+};
+
+let { merge } = require('../util/object');
+let assetsURI = require('../self').data.url();
+let isArray = Array.isArray;
+let method = require('../../method/core');
+
+function isAddonContent({ contentURL }) {
+  return typeof(contentURL) === 'string' && contentURL.indexOf(assetsURI) === 0;
+}
+exports.isAddonContent = isAddonContent;
+
+function hasContentScript({ contentScript, contentScriptFile }) {
+  return (isArray(contentScript) ? contentScript.length > 0 :
+         !!contentScript) ||
+         (isArray(contentScriptFile) ? contentScriptFile.length > 0 :
+         !!contentScriptFile);
+}
+exports.hasContentScript = hasContentScript;
+
+function requiresAddonGlobal(model) {
+  return model.injectInDocument || (isAddonContent(model) && !hasContentScript(model));
+}
+exports.requiresAddonGlobal = requiresAddonGlobal;
+
+function getAttachEventType(model) {
+  if (!model) return null;
+  let when = model.contentScriptWhen;
+  return requiresAddonGlobal(model) ? 'document-element-inserted' :
+         when === 'start' ? 'document-element-inserted' :
+         when === 'ready' ? 'DOMContentLoaded' :
+         when === 'end' ? 'load' :
+         null;
+}
+exports.getAttachEventType = getAttachEventType;
+
+let attach = method('worker-attach');
+exports.attach = attach;
+
+let detach = method('worker-detach');
+exports.detach = detach;
+
+let destroy = method('worker-destroy');
+exports.destroy = destroy;
+
+function WorkerHost (workerFor) {
+  // Define worker properties that just proxy to underlying worker
+  return ['postMessage', 'port', 'url', 'tab'].reduce(function(proto, name) {
+    // Use descriptor properties instead so we can call
+    // the worker function in the context of the worker so we
+    // don't have to create new functions with `fn.bind(worker)`
+    let descriptorProp = {
+      value: function (...args) {
+        let worker = workerFor(this);
+        return worker[name].apply(worker, args);
+      }
+    };
+    
+    let accessorProp = {
+      get: function () { return workerFor(this)[name]; },
+      set: function (value) { workerFor(this)[name] = value; }
+    };
+
+    Object.defineProperty(proto, name, merge({
+      enumerable: true,
+      configurable: false,
+    }, isDescriptor(name) ? descriptorProp : accessorProp));
+    return proto;
+  }, {});
+  
+  function isDescriptor (prop) {
+    return ~['postMessage'].indexOf(prop);
+  }
+}
+exports.WorkerHost = WorkerHost;