--- a/browser/base/content/browser-social.js
+++ b/browser/base/content/browser-social.js
@@ -15,17 +15,20 @@ let SocialUI = {
     Services.obs.addObserver(this, "social:frameworker-error", false);
 
     Services.prefs.addObserver("social.sidebar.open", this, false);
     Services.prefs.addObserver("social.toast-notifications.enabled", this, false);
 
     gBrowser.addEventListener("ActivateSocialFeature", this._activationEventHandler, true, true);
 
     // Called when we enter DOM full-screen mode.
-    window.addEventListener("mozfullscreenchange", function () SocialSidebar.updateSidebar());
+    window.addEventListener("mozfullscreenchange", function () {
+      SocialSidebar.update();
+      SocialChatBar.update();
+    });
 
     Social.init(this._providerReady.bind(this));
   },
 
   // Called on window unload
   uninit: function SocialUI_uninit() {
     Services.obs.removeObserver(this, "social:pref-changed");
     Services.obs.removeObserver(this, "social:ambient-notification-changed");
@@ -49,17 +52,17 @@ let SocialUI = {
     switch (topic) {
       case "social:pref-changed":
         // Exceptions here sometimes don't get reported properly, report them
         // manually :(
         try {
           this.updateToggleCommand();
           SocialShareButton.updateButtonHiddenState();
           SocialToolbar.updateButtonHiddenState();
-          SocialSidebar.updateSidebar();
+          SocialSidebar.update();
           SocialChatBar.update();
           SocialFlyout.unload();
         } catch (e) {
           Components.utils.reportError(e);
           throw e;
         }
         break;
       case "social:ambient-notification-changed":
@@ -73,17 +76,17 @@ let SocialUI = {
         break;
       case "social:frameworker-error":
         if (Social.provider) {
           Social.errorState = "frameworker-error";
           SocialSidebar.setSidebarErrorMessage("frameworker-error");
         }
         break;
       case "nsPref:changed":
-        SocialSidebar.updateSidebar();
+        SocialSidebar.update();
         SocialToolbar.updateButton();
         SocialMenu.populate();
         break;
     }
   },
 
   get toggleCommand() {
     return document.getElementById("Social:Toggle");
@@ -224,32 +227,36 @@ let SocialUI = {
       Social.active = false;
   }
 }
 
 let SocialChatBar = {
   get chatbar() {
     return document.getElementById("pinnedchats");
   },
-  // Whether the chats can be shown for this window.
-  get canShow() {
+  // Whether the chatbar is available for this window.  Note that in full-screen
+  // mode chats are available, but not shown.
+  get isAvailable() {
     if (!SocialUI.haveLoggedInUser())
       return false;
     let docElem = document.documentElement;
     let chromeless = docElem.getAttribute("disablechrome") ||
                      docElem.getAttribute("chromehidden").indexOf("extrachrome") >= 0;
-    return Social.uiVisible && !chromeless && !document.mozFullScreen;
+    return Social.uiVisible && !chromeless;
   },
   openChat: function(aProvider, aURL, aCallback, aMode) {
-    if (this.canShow)
+    if (this.isAvailable)
       this.chatbar.openChat(aProvider, aURL, aCallback, aMode);
   },
   update: function() {
-    if (!this.canShow)
+    if (!this.isAvailable)
       this.chatbar.removeAll();
+    else {
+      this.chatbar.hidden = document.mozFullScreen;
+    }
   },
   focus: function SocialChatBar_focus() {
     let commandDispatcher = gBrowser.ownerDocument.commandDispatcher;
     commandDispatcher.advanceFocusIntoSubtree(this.chatbar);
   }
 }
 
 function sizeSocialPanelToContent(panel, iframe) {
@@ -938,17 +945,17 @@ var SocialToolbar = {
 }
 
 var SocialSidebar = {
   // Called once, after window load, when the Social.provider object is initialized
   init: function SocialSidebar_init() {
     let sbrowser = document.getElementById("social-sidebar-browser");
     this.errorListener = new SocialErrorListener("sidebar");
     this.configureSidebarDocShell(sbrowser.docShell);
-    this.updateSidebar();
+    this.update();
   },
 
   configureSidebarDocShell: function SocialSidebar_configureDocShell(aDocShell) {
     // setting isAppTab causes clicks on untargeted links to open new tabs
     aDocShell.isAppTab = true;
     aDocShell.QueryInterface(Ci.nsIWebProgress)
              .addProgressListener(SocialSidebar.errorListener,
                                   Ci.nsIWebProgress.NOTIFY_STATE_REQUEST |
@@ -976,17 +983,17 @@ var SocialSidebar = {
   setSidebarVisibilityState: function(aEnabled) {
     let sbrowser = document.getElementById("social-sidebar-browser");
     sbrowser.docShell.isActive = aEnabled;
     let evt = sbrowser.contentDocument.createEvent("CustomEvent");
     evt.initCustomEvent(aEnabled ? "socialFrameShow" : "socialFrameHide", true, true, {});
     sbrowser.contentDocument.documentElement.dispatchEvent(evt);
   },
 
-  updateSidebar: function SocialSidebar_updateSidebar() {
+  update: function SocialSidebar_update() {
     clearTimeout(this._unloadTimeoutId);
     // Hide the toggle menu item if the sidebar cannot appear
     let command = document.getElementById("Social:ToggleSidebar");
     command.setAttribute("hidden", this.canShow ? "false" : "true");
 
     // Hide the sidebar if it cannot appear, or has been toggled off.
     // Also set the command "checked" state accordingly.
     let hideSidebar = !this.canShow || !this.opened;

--- a/browser/base/content/socialchat.xml
+++ b/browser/base/content/socialchat.xml
@@ -45,27 +45,16 @@
 
           // let the chat frame know if it is being shown or hidden
           let evt = this.iframe.contentDocument.createEvent("CustomEvent");
           evt.initCustomEvent(val ? "socialFrameShow" : "socialFrameHide", true, true, {});
           this.iframe.contentDocument.documentElement.dispatchEvent(evt);
         </setter>
       </property>
 
-      <method name="init">
-        <parameter name="aProvider"/>
-        <parameter name="aURL"/>
-        <parameter name="aCallback"/>
-        <body><![CDATA[
-          this._callback = aCallback;
-          this.setAttribute("origin", aProvider.origin);
-          this.setAttribute("src", aURL);
-        ]]></body>
-      </method>
-
       <method name="close">
         <body><![CDATA[
           this.parentNode.remove(this);
         ]]></body>
       </method>
 
       <method name="toggle">
         <body><![CDATA[
@@ -371,17 +360,19 @@
             }
             this.chatboxForURL.delete(aURL);
           }
           cb = document.createElementNS("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul", "chatbox");
           if (aMode == "minimized")
             cb.setAttribute("minimized", "true");
           this.selectedChat = cb;
           this.insertBefore(cb, this.firstChild);
-          cb.init(aProvider, aURL, aCallback);
+          cb._callback = aCallback;
+          cb.setAttribute("origin", aProvider.origin);
+          cb.setAttribute("src", aURL);
           this.chatboxForURL.set(aURL, Cu.getWeakReference(cb));
           this.resize();
         ]]></body>
       </method>
 
       <method name="resize">
         <body><![CDATA[
         // Checks the current size against the collapsed state of children