The Tor Browser / file revision

 // Utilities for running tests in an e10s environment.

 // There are some tricks/shortcuts that test code takes that we don't see

 // in the real browser code.  These include setting content.location.href

 // (which doesn't work in test code with e10s enabled as the document object

 // is yet to be created), waiting for certain events the main browser doesn't

 // care about and so doesn't normally get special support, eg, the "pageshow"

 // or "load" events).

 // So we make some hacks to pretend these work in the test suite.

 // Ideally all these hacks could be removed, but this can only happen when

 // the tests are refactored to not use these tricks.  But this would be a huge

 // amount of work and is unlikely to happen anytime soon...

 const CONTENT_URL = "chrome://mochikit/content/mochitest-e10s-utils-content.js";

 // This is an object that is used as the "location" on a remote document or

 // window.  It will be overwritten as the real document and window are made

 // available.

 let locationStub = function(browser) {

   this.browser = browser;

 };

 locationStub.prototype = {

   get href() {

     return this.browser.webNavigation.currentURI.spec;

   },

   set href(val) {

     this.browser.loadURI(val);

   },

   assign: function(url) {

     this.href = url;

   }

 };

 // This object is used in place of contentWindow while we wait for it to be

 // overwritten as the real window becomes available.

 let TemporaryWindowStub = function(browser) {

   this._locationStub = new locationStub(browser);

 };

 TemporaryWindowStub.prototype = {

   // save poor developers from getting confused about why the window isn't

   // working like a window should..

   toString: function() {

     return "[Window Stub for e10s tests]";

   },

   get location() {

     return this._locationStub;

   },

   set location(val) {

     this._locationStub.href = val;

   },

   get document() {

     // so tests can say: document.location....

     return this;

   }

 };

 // An observer called when a new remote browser element is created.  We replace

 // the _contentWindow in new browsers with our TemporaryWindowStub object.

 function observeNewFrameloader(subject, topic, data) {

   let browser = subject.QueryInterface(Ci.nsIFrameLoader).ownerElement;

   browser._contentWindow = new TemporaryWindowStub(browser);

 }

 function e10s_init() {

   // Use the global message manager to inject a content script into all browsers.

   let globalMM = Cc["@mozilla.org/globalmessagemanager;1"]

                    .getService(Ci.nsIMessageListenerManager);

   globalMM.loadFrameScript(CONTENT_URL, true);

   globalMM.addMessageListener("Test:Event", function(message) {

     let event = document.createEvent('HTMLEvents');

     event.initEvent(message.data.name, true, true, {});

     message.target.dispatchEvent(event);

   });

   // We add an observer so we can notice new <browser> elements created

   Services.obs.addObserver(observeNewFrameloader, "remote-browser-shown", false);

   // Listen for an 'oop-browser-crashed' event and log it so people analysing

   // test logs have a clue about what is going on.

   window.addEventListener("oop-browser-crashed", (event) => {

     let uri = event.target.currentURI;

     Cu.reportError("remote browser crashed while on " +

                    (uri ? uri.spec : "<unknown>") + "\n");

   }, true);

 }