Bug 616907 - Convert private-browsing events to style described in bu…

…g 593921. r=myk

packages/addon-kit/docs/private-browsing.md

@@ -2,34 +2,29 @@
 <!-- edited by Noelle Murata [fiveinchpixie@gmail.com]  -->
 <!-- contributed by Irakli Gozalishvili [gozala@mozilla.com] -->
 
-
-The `private-browsing` module allows you to access the private browsing service
-- detecting if it is active and adding callbacks for transitioning into and out
-of private browsing mode.
-
-Private browsing is a singleton, so in most cases it will be easiest to store it
-in a variable.
-
-    var pb = require("private-browsing");
+The `private-browsing` module allows you to access Firefox's private browsing
+mode, detecting if it is active and when its state changes.
 
 ## Events ##
 
 When the browser starts or stops private browsing mode, the following events
-are emitted:
+are emitted.  In each case, listeners are passed an event object that has a
+single property `emitter` whose value is the private browsing module itself.
 
 ### start ###
 Emitted when the browser starts private browsing mode.
 
-    pb.on("start", function() {
+    var pb = require("private-browsing");
+    pb.on("start", function(event) {
       // Do something when the browser starts private browsing mode.
     });
 
 
 ### stop ###
 Emitted when the browser stops private browsing mode.
 
-
-    pb.on("stop", function() {
+    var pb = require("private-browsing");
+    pb.on("stop", function(event) {
       // Do something when the browser stops private browsing mode.
     });
 

packages/addon-kit/lib/private-browsing.js

@@ -56,7 +56,7 @@ if (require("xul-app").is("Firefox")) {
 const privateBrowsing = EventEmitter.compose({
   constructor: function PrivateBrowsing() {
     // Binding method to instance since it will be used with `setTimeout`.
-    this._emit = this._emit.bind(this);
+    this._emitEventObject = this._emitEventObject.bind(this);
     this.unload = this.unload.bind(this);
     // Report unhandled errors from listeners
     this.on("error", console.exception.bind(console));
@@ -74,7 +74,8 @@ const privateBrowsing = EventEmitter.compose({
   // We don't need to do anything with cancel here.
   onTransition: function onTransition() {
     let isActive = this._isActive = pbService.privateBrowsingEnabled;
-    setTimeout(this._emit, 0, isActive ? ON_START : ON_STOP);
+    setTimeout(this._emitEventObject, 0, isActive ? ON_START : ON_STOP, {},
+               exports);
   },
   get isActive() this._isActive,
   set isActive(value) {

packages/addon-kit/tests/test-private-browsing.js

@@ -73,7 +73,11 @@ if (pbService) {
 
   exports.testStart = function(test) {
     test.waitUntilDone();
-    pb.on("start", function onStart() {
+    pb.on("start", function onStart(evt) {
+      test.assertEqual(this, pb, "`this` should be private-browsing module");
+      test.assert(!!evt, "Listener should be passed event object");
+      test.assertEqual(evt.emitter, pb,
+                       "event.emitter should be private-browsing module");
       test.assert(pbService.privateBrowsingEnabled,
                   'private mode is active when "start" event is emitted');
       test.assert(pb.isActive,
@@ -86,7 +90,11 @@ if (pbService) {
 
   exports.testStop = function(test) {
     test.waitUntilDone();
-    pb.on("stop", function onStop() {
+    pb.on("stop", function onStop(evt) {
+      test.assertEqual(this, pb, "`this` should be private-browsing module");
+      test.assert(!!evt, "Listener should be passed event object");
+      test.assertEqual(evt.emitter, pb,
+                       "event.emitter should be private-browsing module");
       test.assertEqual(pbService.privateBrowsingEnabled, false,
                        "private mode is disabled when stop event is emitted");
       test.assertEqual(pb.isActive, false,