Add m-esr52 at 52.6.0

1 files changed, 1794 insertions, 0 deletions

diff --git a/mobile/android/components/SessionStore.js b/mobile/android/components/SessionStore.js
new file mode 100644
index 000000000..18ac6bf94
--- /dev/null
+++ b/mobile/android/components/SessionStore.js
@@ -0,0 +1,1794 @@
+/* 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/. */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+const Cr = Components.results;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "Task", "resource://gre/modules/Task.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS", "resource://gre/modules/osfile.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Messaging", "resource://gre/modules/Messaging.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils", "resource://gre/modules/PrivateBrowsingUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "FormData", "resource://gre/modules/FormData.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "ScrollPosition", "resource://gre/modules/ScrollPosition.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "TelemetryStopwatch", "resource://gre/modules/TelemetryStopwatch.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Log", "resource://gre/modules/AndroidLog.jsm", "AndroidLog");
+XPCOMUtils.defineLazyModuleGetter(this, "SharedPreferences", "resource://gre/modules/SharedPreferences.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Utils", "resource://gre/modules/sessionstore/Utils.jsm");
+XPCOMUtils.defineLazyServiceGetter(this, "serializationHelper",
+                                   "@mozilla.org/network/serialization-helper;1",
+                                   "nsISerializationHelper");
+
+function dump(a) {
+  Services.console.logStringMessage(a);
+}
+
+let loggingEnabled = false;
+
+function log(a) {
+  if (!loggingEnabled) {
+    return;
+  }
+  Log.d("SessionStore", a);
+}
+
+// -----------------------------------------------------------------------
+// Session Store
+// -----------------------------------------------------------------------
+
+const STATE_STOPPED = 0;
+const STATE_RUNNING = 1;
+const STATE_QUITTING = -1;
+const STATE_QUITTING_FLUSHED = -2;
+
+const PRIVACY_NONE = 0;
+const PRIVACY_ENCRYPTED = 1;
+const PRIVACY_FULL = 2;
+
+const PREFS_RESTORE_FROM_CRASH = "browser.sessionstore.resume_from_crash";
+const PREFS_MAX_CRASH_RESUMES = "browser.sessionstore.max_resumed_crashes";
+
+const MINIMUM_SAVE_DELAY = 2000;
+// We reduce the delay in background because we could be killed at any moment,
+// however we don't set it to 0 in order to allow for multiple events arriving
+// one after the other to be batched together in one write operation.
+const MINIMUM_SAVE_DELAY_BACKGROUND = 200;
+
+function SessionStore() { }
+
+SessionStore.prototype = {
+  classID: Components.ID("{8c1f07d6-cba3-4226-a315-8bd43d67d032}"),
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISessionStore,
+                                         Ci.nsIDOMEventListener,
+                                         Ci.nsIObserver,
+                                         Ci.nsISupportsWeakReference]),
+
+  _windows: {},
+  _lastSaveTime: 0,
+  _lastBackupTime: 0,
+  _interval: 10000,
+  _backupInterval: 120000, // 2 minutes
+  _minSaveDelay: MINIMUM_SAVE_DELAY,
+  _maxTabsUndo: 5,
+  _pendingWrite: 0,
+  _scrollSavePending: null,
+  _writeInProgress: false,
+
+  // We only want to start doing backups if we've successfully
+  // written the session data at least once.
+  _sessionDataIsGood: false,
+
+  // The index where the most recently closed tab was in the tabs array
+  // when it was closed.
+  _lastClosedTabIndex: -1,
+
+  // Whether or not to send notifications for changes to the closed tabs.
+  _notifyClosedTabs: false,
+
+  // If we're simultaneously closing both a tab and Firefox, we don't want
+  // to bother reloading the newly selected tab if it is zombified.
+  // The Java UI will tell us which tab to watch out for.
+  _keepAsZombieTabId: -1,
+
+  init: function ss_init() {
+    loggingEnabled = Services.prefs.getBoolPref("browser.sessionstore.debug_logging");
+
+    // Get file references
+    this._sessionFile = Services.dirsvc.get("ProfD", Ci.nsILocalFile);
+    this._sessionFileBackup = this._sessionFile.clone();
+    this._sessionFilePrevious = this._sessionFile.clone();
+    this._sessionFileTemp = this._sessionFile.clone();
+    this._sessionFile.append("sessionstore.js"); // The main session store save file.
+    this._sessionFileBackup.append("sessionstore.bak"); // A backup copy to guard against interrupted writes.
+    this._sessionFilePrevious.append("sessionstore.old"); // The previous session's file, used for what used to be the "Tabs from last time".
+    this._sessionFileTemp.append(this._sessionFile.leafName + ".tmp"); // Temporary file for writing changes to disk.
+
+    this._loadState = STATE_STOPPED;
+    this._startupRestoreFinished = false;
+
+    this._interval = Services.prefs.getIntPref("browser.sessionstore.interval");
+    this._backupInterval = Services.prefs.getIntPref("browser.sessionstore.backupInterval");
+    this._maxTabsUndo = Services.prefs.getIntPref("browser.sessionstore.max_tabs_undo");
+
+    // Copy changes in Gecko settings to their Java counterparts,
+    // so the startup code can access them
+    Services.prefs.addObserver(PREFS_RESTORE_FROM_CRASH, function() {
+      SharedPreferences.forApp().setBoolPref(PREFS_RESTORE_FROM_CRASH,
+        Services.prefs.getBoolPref(PREFS_RESTORE_FROM_CRASH));
+    }, false);
+    Services.prefs.addObserver(PREFS_MAX_CRASH_RESUMES, function() {
+      SharedPreferences.forApp().setIntPref(PREFS_MAX_CRASH_RESUMES,
+        Services.prefs.getIntPref(PREFS_MAX_CRASH_RESUMES));
+    }, false);
+  },
+
+  _clearDisk: function ss_clearDisk() {
+    this._sessionDataIsGood = false;
+
+    if (this._loadState > STATE_QUITTING) {
+      OS.File.remove(this._sessionFile.path);
+      OS.File.remove(this._sessionFileBackup.path);
+      OS.File.remove(this._sessionFilePrevious.path);
+      OS.File.remove(this._sessionFileTemp.path);
+    } else { // We're shutting down and must delete synchronously
+      if (this._sessionFile.exists()) { this._sessionFile.remove(false); }
+      if (this._sessionFileBackup.exists()) { this._sessionFileBackup.remove(false); }
+      if (this._sessionFileBackup.exists()) { this._sessionFilePrevious.remove(false); }
+      if (this._sessionFileBackup.exists()) { this._sessionFileTemp.remove(false); }
+    }
+  },
+
+  observe: function ss_observe(aSubject, aTopic, aData) {
+    let self = this;
+    let observerService = Services.obs;
+    switch (aTopic) {
+      case "app-startup":
+        observerService.addObserver(this, "final-ui-startup", true);
+        observerService.addObserver(this, "domwindowopened", true);
+        observerService.addObserver(this, "domwindowclosed", true);
+        observerService.addObserver(this, "browser:purge-session-history", true);
+        observerService.addObserver(this, "quit-application-requested", true);
+        observerService.addObserver(this, "quit-application-proceeding", true);
+        observerService.addObserver(this, "quit-application", true);
+        observerService.addObserver(this, "Session:Restore", true);
+        observerService.addObserver(this, "Session:NotifyLocationChange", true);
+        observerService.addObserver(this, "Tab:KeepZombified", true);
+        observerService.addObserver(this, "application-background", true);
+        observerService.addObserver(this, "application-foreground", true);
+        observerService.addObserver(this, "ClosedTabs:StartNotifications", true);
+        observerService.addObserver(this, "ClosedTabs:StopNotifications", true);
+        observerService.addObserver(this, "last-pb-context-exited", true);
+        observerService.addObserver(this, "Session:RestoreRecentTabs", true);
+        observerService.addObserver(this, "Tabs:OpenMultiple", true);
+        break;
+      case "final-ui-startup":
+        observerService.removeObserver(this, "final-ui-startup");
+        this.init();
+        break;
+      case "domwindowopened": {
+        let window = aSubject;
+        window.addEventListener("load", function() {
+          self.onWindowOpen(window);
+          window.removeEventListener("load", arguments.callee, false);
+        }, false);
+        break;
+      }
+      case "domwindowclosed": // catch closed windows
+        this.onWindowClose(aSubject);
+        break;
+      case "quit-application-requested":
+        log("quit-application-requested");
+        // Get a current snapshot of all windows
+        if (this._pendingWrite) {
+          this._forEachBrowserWindow(function(aWindow) {
+            self._collectWindowData(aWindow);
+          });
+        }
+        break;
+      case "quit-application-proceeding":
+        log("quit-application-proceeding");
+        // Freeze the data at what we've got (ignoring closing windows)
+        this._loadState = STATE_QUITTING;
+        break;
+      case "quit-application":
+        log("quit-application");
+        observerService.removeObserver(this, "domwindowopened");
+        observerService.removeObserver(this, "domwindowclosed");
+        observerService.removeObserver(this, "quit-application-requested");
+        observerService.removeObserver(this, "quit-application-proceeding");
+        observerService.removeObserver(this, "quit-application");
+
+        // Flush all pending writes to disk now
+        this.flushPendingState();
+        this._loadState = STATE_QUITTING_FLUSHED;
+
+        break;
+      case "browser:purge-session-history": // catch sanitization
+        log("browser:purge-session-history");
+        this._clearDisk();
+
+        // Clear all data about closed tabs
+        for (let [ssid, win] of Object.entries(this._windows))
+          win.closedTabs = [];
+
+        this._lastClosedTabIndex = -1;
+
+        if (this._loadState == STATE_RUNNING) {
+          // Save the purged state immediately
+          this.saveState();
+        } else if (this._loadState <= STATE_QUITTING) {
+          this.saveStateDelayed();
+          if (this._loadState == STATE_QUITTING_FLUSHED) {
+            this.flushPendingState();
+          }
+        }
+
+        Services.obs.notifyObservers(null, "sessionstore-state-purge-complete", "");
+        if (this._notifyClosedTabs) {
+          this._sendClosedTabsToJava(Services.wm.getMostRecentWindow("navigator:browser"));
+        }
+        break;
+      case "timer-callback":
+        if (this._loadState == STATE_RUNNING) {
+          // Timer call back for delayed saving
+          this._saveTimer = null;
+          log("timer-callback, pendingWrite = " + this._pendingWrite);
+          if (this._pendingWrite) {
+            this.saveState();
+          }
+        }
+        break;
+      case "Session:Restore": {
+        Services.obs.removeObserver(this, "Session:Restore");
+        if (aData) {
+          // Be ready to handle any restore failures by making sure we have a valid tab opened
+          let window = Services.wm.getMostRecentWindow("navigator:browser");
+          let restoreCleanup = {
+            observe: function (aSubject, aTopic, aData) {
+              Services.obs.removeObserver(restoreCleanup, "sessionstore-windows-restored");
+
+              if (window.BrowserApp.tabs.length == 0) {
+                window.BrowserApp.addTab("about:home", {
+                  selected: true
+                });
+              }
+              // Normally, _restoreWindow() will have set this to true already,
+              // but we want to make sure it's set even in case of a restore failure.
+              this._startupRestoreFinished = true;
+              log("startupRestoreFinished = true (through notification)");
+            }.bind(this)
+          };
+          Services.obs.addObserver(restoreCleanup, "sessionstore-windows-restored", false);
+
+          // Do a restore, triggered by Java
+          let data = JSON.parse(aData);
+          this.restoreLastSession(data.sessionString);
+        } else {
+          // Not doing a restore; just send restore message
+          this._startupRestoreFinished = true;
+          log("startupRestoreFinished = true");
+          Services.obs.notifyObservers(null, "sessionstore-windows-restored", "");
+        }
+        break;
+      }
+      case "Session:NotifyLocationChange": {
+        let browser = aSubject;
+
+        if (browser.__SS_restoreReloadPending && this._startupRestoreFinished) {
+          delete browser.__SS_restoreReloadPending;
+          log("remove restoreReloadPending");
+        }
+
+        if (browser.__SS_restoreDataOnLocationChange) {
+          delete browser.__SS_restoreDataOnLocationChange;
+          this._restoreZoom(browser.__SS_data.scrolldata, browser);
+        }
+        break;
+      }
+      case "Tabs:OpenMultiple": {
+        let data = JSON.parse(aData);
+
+        this._openTabs(data);
+
+        if (data.shouldNotifyTabsOpenedToJava) {
+          Messaging.sendRequest({
+            type: "Tabs:TabsOpened"
+          });
+        }
+        break;
+      }
+      case "Tab:KeepZombified": {
+        if (aData >= 0) {
+          this._keepAsZombieTabId = aData;
+          log("Tab:KeepZombified " + aData);
+        }
+        break;
+      }
+      case "application-background":
+        // We receive this notification when Android's onPause callback is
+        // executed. After onPause, the application may be terminated at any
+        // point without notice; therefore, we must synchronously write out any
+        // pending save state to ensure that this data does not get lost.
+        log("application-background");
+        // Tab events dispatched immediately before the application was backgrounded
+        // might actually arrive after this point, therefore save them without delay.
+        if (this._loadState == STATE_RUNNING) {
+          this._interval = 0;
+          this._minSaveDelay = MINIMUM_SAVE_DELAY_BACKGROUND; // A small delay allows successive tab events to be batched together.
+          this.flushPendingState();
+        }
+        break;
+      case "application-foreground":
+        // Reset minimum interval between session store writes back to default.
+        log("application-foreground");
+        this._interval = Services.prefs.getIntPref("browser.sessionstore.interval");
+        this._minSaveDelay = MINIMUM_SAVE_DELAY;
+
+        // If we skipped restoring a zombified tab before backgrounding,
+        // we might have to do it now instead.
+        let window = Services.wm.getMostRecentWindow("navigator:browser");
+        if (window) { // Might not yet be ready during a cold startup.
+          let tab = window.BrowserApp.selectedTab;
+          if (tab.browser.__SS_restore) {
+            this._restoreZombieTab(tab.browser, tab.id);
+          }
+        }
+        break;
+      case "ClosedTabs:StartNotifications":
+        this._notifyClosedTabs = true;
+        log("ClosedTabs:StartNotifications");
+        this._sendClosedTabsToJava(Services.wm.getMostRecentWindow("navigator:browser"));
+        break;
+      case "ClosedTabs:StopNotifications":
+        this._notifyClosedTabs = false;
+        log("ClosedTabs:StopNotifications");
+        break;
+      case "last-pb-context-exited":
+        // Clear private closed tab data when we leave private browsing.
+        for (let window of Object.values(this._windows)) {
+          window.closedTabs = window.closedTabs.filter(tab => !tab.isPrivate);
+        }
+        this._lastClosedTabIndex = -1;
+        break;
+      case "Session:RestoreRecentTabs": {
+        let data = JSON.parse(aData);
+        this._restoreTabs(data);
+        break;
+      }
+    }
+  },
+
+  handleEvent: function ss_handleEvent(aEvent) {
+    let window = aEvent.currentTarget.ownerDocument.defaultView;
+    switch (aEvent.type) {
+      case "TabOpen": {
+        let browser = aEvent.target;
+        log("TabOpen for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabAdd(window, browser);
+        break;
+      }
+      case "TabClose": {
+        let browser = aEvent.target;
+        log("TabClose for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabClose(window, browser, aEvent.detail);
+        this.onTabRemove(window, browser);
+        break;
+      }
+      case "TabPreZombify": {
+        let browser = aEvent.target;
+        log("TabPreZombify for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabRemove(window, browser, true);
+        break;
+      }
+      case "TabPostZombify": {
+        let browser = aEvent.target;
+        log("TabPostZombify for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabAdd(window, browser, true);
+        break;
+      }
+      case "TabSelect": {
+        let browser = aEvent.target;
+        log("TabSelect for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabSelect(window, browser);
+        break;
+      }
+      case "DOMTitleChanged": {
+        // Use DOMTitleChanged to detect page loads over alternatives.
+        // onLocationChange happens too early, so we don't have the page title
+        // yet; pageshow happens too late, so we could lose session data if the
+        // browser were killed.
+        let browser = aEvent.currentTarget;
+        log("DOMTitleChanged for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabLoad(window, browser);
+        break;
+      }
+      case "load": {
+        let browser = aEvent.currentTarget;
+
+        // Skip subframe loads.
+        if (browser.contentDocument !== aEvent.originalTarget) {
+          return;
+        }
+
+        // Handle restoring the text data into the content and frames.
+        // We wait until the main content and all frames are loaded
+        // before trying to restore this data.
+        log("load for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        if (browser.__SS_restoreDataOnLoad) {
+          delete browser.__SS_restoreDataOnLoad;
+          this._restoreTextData(browser.__SS_data.formdata, browser);
+        }
+        break;
+      }
+      case "pageshow":
+      case "AboutReaderContentReady": {
+        let browser = aEvent.currentTarget;
+
+        // Skip subframe pageshows.
+        if (browser.contentDocument !== aEvent.originalTarget) {
+          return;
+        }
+
+        if (browser.currentURI.spec.startsWith("about:reader") &&
+            !browser.contentDocument.body.classList.contains("loaded")) {
+          // Don't restore the scroll position of an about:reader page at this point;
+          // wait for the custom event dispatched from AboutReader.jsm instead.
+          return;
+        }
+
+        // Restoring the scroll position needs to happen after the zoom level has been
+        // restored, which is done by the MobileViewportManager either on first paint
+        // or on load, whichever comes first.
+        // In the latter case, our load handler runs before the MVM's one, which is the
+        // wrong way around, so we have to use a later event instead.
+        log(aEvent.type + " for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        if (browser.__SS_restoreDataOnPageshow) {
+          delete browser.__SS_restoreDataOnPageshow;
+          this._restoreScrollPosition(browser.__SS_data.scrolldata, browser);
+        } else {
+          // We're not restoring, capture the initial scroll position on pageshow.
+          this.onTabScroll(window, browser);
+        }
+        break;
+      }
+      case "change":
+      case "input":
+      case "DOMAutoComplete": {
+        let browser = aEvent.currentTarget;
+        log("TabInput for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        this.onTabInput(window, browser);
+        break;
+      }
+      case "resize":
+      case "scroll": {
+        let browser = aEvent.currentTarget;
+        // Duplicated logging check to avoid calling getTabForBrowser on each scroll event.
+        if (loggingEnabled) {
+          log(aEvent.type + " for tab " + window.BrowserApp.getTabForBrowser(browser).id);
+        }
+        if (!this._scrollSavePending) {
+          this._scrollSavePending =
+            window.setTimeout(() => {
+              this._scrollSavePending = null;
+              this.onTabScroll(window, browser);
+            }, 500);
+        }
+        break;
+      }
+    }
+  },
+
+  onWindowOpen: function ss_onWindowOpen(aWindow) {
+    // Return if window has already been initialized
+    if (aWindow && aWindow.__SSID && this._windows[aWindow.__SSID]) {
+      return;
+    }
+
+    // Ignore non-browser windows and windows opened while shutting down
+    if (aWindow.document.documentElement.getAttribute("windowtype") != "navigator:browser" || this._loadState <= STATE_QUITTING) {
+      return;
+    }
+
+    // Assign it a unique identifier (timestamp) and create its data object
+    aWindow.__SSID = "window" + Date.now();
+    this._windows[aWindow.__SSID] = { tabs: [], selected: 0, closedTabs: [] };
+
+    // Perform additional initialization when the first window is loading
+    if (this._loadState == STATE_STOPPED) {
+      this._loadState = STATE_RUNNING;
+      this._lastSaveTime = Date.now();
+    }
+
+    // Add tab change listeners to all already existing tabs
+    let tabs = aWindow.BrowserApp.tabs;
+    for (let i = 0; i < tabs.length; i++)
+      this.onTabAdd(aWindow, tabs[i].browser, true);
+
+    // Notification of tab add/remove/selection/zombification
+    let browsers = aWindow.document.getElementById("browsers");
+    browsers.addEventListener("TabOpen", this, true);
+    browsers.addEventListener("TabClose", this, true);
+    browsers.addEventListener("TabSelect", this, true);
+    browsers.addEventListener("TabPreZombify", this, true);
+    browsers.addEventListener("TabPostZombify", this, true);
+  },
+
+  onWindowClose: function ss_onWindowClose(aWindow) {
+    // Ignore windows not tracked by SessionStore
+    if (!aWindow.__SSID || !this._windows[aWindow.__SSID]) {
+      return;
+    }
+
+    let browsers = aWindow.document.getElementById("browsers");
+    browsers.removeEventListener("TabOpen", this, true);
+    browsers.removeEventListener("TabClose", this, true);
+    browsers.removeEventListener("TabSelect", this, true);
+    browsers.removeEventListener("TabPreZombify", this, true);
+    browsers.removeEventListener("TabPostZombify", this, true);
+
+    if (this._loadState == STATE_RUNNING) {
+      // Update all window data for a last time
+      this._collectWindowData(aWindow);
+
+      // Clear this window from the list
+      delete this._windows[aWindow.__SSID];
+
+      // Save the state without this window to disk
+      this.saveStateDelayed();
+    }
+
+    let tabs = aWindow.BrowserApp.tabs;
+    for (let i = 0; i < tabs.length; i++)
+      this.onTabRemove(aWindow, tabs[i].browser, true);
+
+    delete aWindow.__SSID;
+  },
+
+  onTabAdd: function ss_onTabAdd(aWindow, aBrowser, aNoNotification) {
+    // Use DOMTitleChange to catch the initial load and restore history
+    aBrowser.addEventListener("DOMTitleChanged", this, true);
+
+    // Use load to restore text data
+    aBrowser.addEventListener("load", this, true);
+
+    // Gecko might set the initial zoom level after the JS "load" event,
+    // so we have to restore zoom and scroll position after that.
+    aBrowser.addEventListener("pageshow", this, true);
+    aBrowser.addEventListener("AboutReaderContentReady", this, true);
+
+    // Use a combination of events to watch for text data changes
+    aBrowser.addEventListener("change", this, true);
+    aBrowser.addEventListener("input", this, true);
+    aBrowser.addEventListener("DOMAutoComplete", this, true);
+
+    // Record the current scroll position and zoom level.
+    aBrowser.addEventListener("scroll", this, true);
+    aBrowser.addEventListener("resize", this, true);
+
+    log("onTabAdd() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id +
+        ", aNoNotification = " + aNoNotification);
+    if (!aNoNotification) {
+      this.saveStateDelayed();
+    }
+    this._updateCrashReportURL(aWindow);
+  },
+
+  onTabRemove: function ss_onTabRemove(aWindow, aBrowser, aNoNotification) {
+    // Cleanup event listeners
+    aBrowser.removeEventListener("DOMTitleChanged", this, true);
+    aBrowser.removeEventListener("load", this, true);
+    aBrowser.removeEventListener("pageshow", this, true);
+    aBrowser.removeEventListener("AboutReaderContentReady", this, true);
+    aBrowser.removeEventListener("change", this, true);
+    aBrowser.removeEventListener("input", this, true);
+    aBrowser.removeEventListener("DOMAutoComplete", this, true);
+    aBrowser.removeEventListener("scroll", this, true);
+    aBrowser.removeEventListener("resize", this, true);
+
+    delete aBrowser.__SS_data;
+
+    log("onTabRemove() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id +
+        ", aNoNotification = " + aNoNotification);
+    if (!aNoNotification) {
+      this.saveStateDelayed();
+    }
+  },
+
+  onTabClose: function ss_onTabClose(aWindow, aBrowser, aTabIndex) {
+    if (this._maxTabsUndo == 0) {
+      return;
+    }
+
+    if (aWindow.BrowserApp.tabs.length > 0) {
+      // Bundle this browser's data and extra data and save in the closedTabs
+      // window property
+      let data = aBrowser.__SS_data || {};
+      data.extData = aBrowser.__SS_extdata || {};
+
+      this._windows[aWindow.__SSID].closedTabs.unshift(data);
+      let length = this._windows[aWindow.__SSID].closedTabs.length;
+      if (length > this._maxTabsUndo) {
+        this._windows[aWindow.__SSID].closedTabs.splice(this._maxTabsUndo, length - this._maxTabsUndo);
+      }
+
+      this._lastClosedTabIndex = aTabIndex;
+
+      if (this._notifyClosedTabs) {
+        this._sendClosedTabsToJava(aWindow);
+      }
+
+      log("onTabClose() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id);
+      let evt = new Event("SSTabCloseProcessed", {"bubbles":true, "cancelable":false});
+      aBrowser.dispatchEvent(evt);
+    }
+  },
+
+  onTabLoad: function ss_onTabLoad(aWindow, aBrowser) {
+    // If this browser belongs to a zombie tab or the initial restore hasn't yet finished,
+    // skip any session save activity.
+    if (aBrowser.__SS_restore || !this._startupRestoreFinished || aBrowser.__SS_restoreReloadPending) {
+      return;
+    }
+
+    // Ignore a transient "about:blank"
+    if (!aBrowser.canGoBack && aBrowser.currentURI.spec == "about:blank") {
+      return;
+    }
+
+    let history = aBrowser.sessionHistory;
+
+    // Serialize the tab data
+    let entries = [];
+    let index = history.index + 1;
+    for (let i = 0; i < history.count; i++) {
+      let historyEntry = history.getEntryAtIndex(i, false);
+      // Don't try to restore wyciwyg URLs
+      if (historyEntry.URI.schemeIs("wyciwyg")) {
+        // Adjust the index to account for skipped history entries
+        if (i <= history.index) {
+          index--;
+        }
+        continue;
+      }
+      let entry = this._serializeHistoryEntry(historyEntry);
+      entries.push(entry);
+    }
+    let data = { entries: entries, index: index };
+
+    let formdata;
+    let scrolldata;
+    if (aBrowser.__SS_data) {
+      formdata = aBrowser.__SS_data.formdata;
+      scrolldata = aBrowser.__SS_data.scrolldata;
+    }
+    delete aBrowser.__SS_data;
+
+    this._collectTabData(aWindow, aBrowser, data);
+    if (aBrowser.__SS_restoreDataOnLoad || aBrowser.__SS_restoreDataOnPageshow) {
+      // If the tab has been freshly restored and the "load" or "pageshow"
+      // events haven't yet fired, we need to preserve any form data and
+      // scroll positions that might have been present.
+      aBrowser.__SS_data.formdata = formdata;
+      aBrowser.__SS_data.scrolldata = scrolldata;
+    } else {
+      // When navigating via the forward/back buttons, Gecko restores
+      // the form data all by itself and doesn't invoke any input events.
+      // As _collectTabData() doesn't save any form data, we need to manually
+      // capture it to bridge the time until the next input event arrives.
+      this.onTabInput(aWindow, aBrowser);
+    }
+
+    log("onTabLoad() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id);
+    let evt = new Event("SSTabDataUpdated", {"bubbles":true, "cancelable":false});
+    aBrowser.dispatchEvent(evt);
+    this.saveStateDelayed();
+
+    this._updateCrashReportURL(aWindow);
+  },
+
+  onTabSelect: function ss_onTabSelect(aWindow, aBrowser) {
+    if (this._loadState != STATE_RUNNING) {
+      return;
+    }
+
+    let browsers = aWindow.document.getElementById("browsers");
+    let index = browsers.selectedIndex;
+    this._windows[aWindow.__SSID].selected = parseInt(index) + 1; // 1-based
+
+    let tabId = aWindow.BrowserApp.getTabForBrowser(aBrowser).id;
+
+    // Restore the resurrected browser
+    if (aBrowser.__SS_restore) {
+      if (tabId != this._keepAsZombieTabId) {
+        this._restoreZombieTab(aBrowser, tabId);
+      } else {
+        log("keeping as zombie tab " + tabId);
+      }
+    }
+    // The tab id passed through Tab:KeepZombified is valid for one TabSelect only.
+    this._keepAsZombieTabId = -1;
+
+    log("onTabSelect() ran for tab " + tabId);
+    this.saveStateDelayed();
+    this._updateCrashReportURL(aWindow);
+
+    // If the selected tab has changed while listening for closed tab
+    // notifications, we may have switched between different private browsing
+    // modes.
+    if (this._notifyClosedTabs) {
+      this._sendClosedTabsToJava(aWindow);
+    }
+  },
+
+  _restoreZombieTab: function ss_restoreZombieTab(aBrowser, aTabId) {
+    let data = aBrowser.__SS_data;
+    this._restoreTab(data, aBrowser);
+
+    delete aBrowser.__SS_restore;
+    aBrowser.removeAttribute("pending");
+    log("restoring zombie tab " + aTabId);
+  },
+
+  onTabInput: function ss_onTabInput(aWindow, aBrowser) {
+    // If this browser belongs to a zombie tab or the initial restore hasn't yet finished,
+    // skip any session save activity.
+    if (aBrowser.__SS_restore || !this._startupRestoreFinished || aBrowser.__SS_restoreReloadPending) {
+      return;
+    }
+
+    // Don't bother trying to save text data if we don't have history yet
+    let data = aBrowser.__SS_data;
+    if (!data || data.entries.length == 0) {
+      return;
+    }
+
+    // Start with storing the main content
+    let content = aBrowser.contentWindow;
+
+    // If the main content document has an associated URL that we are not
+    // allowed to store data for, bail out. We explicitly discard data for any
+    // children as well even if storing data for those frames would be allowed.
+    if (!this.checkPrivacyLevel(content.document.documentURI)) {
+      return;
+    }
+
+    // Store the main content
+    let formdata = FormData.collect(content) || {};
+
+    // Loop over direct child frames, and store the text data
+    let children = [];
+    for (let i = 0; i < content.frames.length; i++) {
+      let frame = content.frames[i];
+      if (!this.checkPrivacyLevel(frame.document.documentURI)) {
+        continue;
+      }
+
+      let result = FormData.collect(frame);
+      if (result && Object.keys(result).length) {
+        children[i] = result;
+      }
+    }
+
+    // If any frame had text data, add it to the main form data
+    if (children.length) {
+      formdata.children = children;
+    }
+
+    // If we found any form data, main content or frames, let's save it
+    if (Object.keys(formdata).length) {
+      data.formdata = formdata;
+      log("onTabInput() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id);
+      this.saveStateDelayed();
+    }
+  },
+
+  onTabScroll: function ss_onTabScroll(aWindow, aBrowser) {
+    // If we've been called directly, cancel any pending timeouts.
+    if (this._scrollSavePending) {
+      aWindow.clearTimeout(this._scrollSavePending);
+      this._scrollSavePending = null;
+      log("onTabScroll() clearing pending timeout");
+    }
+
+    // If this browser belongs to a zombie tab or the initial restore hasn't yet finished,
+    // skip any session save activity.
+    if (aBrowser.__SS_restore || !this._startupRestoreFinished || aBrowser.__SS_restoreReloadPending) {
+      return;
+    }
+
+    // Don't bother trying to save scroll positions if we don't have history yet.
+    let data = aBrowser.__SS_data;
+    if (!data || data.entries.length == 0) {
+      return;
+    }
+
+    // Neither bother if we're yet to restore the previous scroll position.
+    if (aBrowser.__SS_restoreDataOnLoad || aBrowser.__SS_restoreDataOnPageshow) {
+      return;
+    }
+
+    // Start with storing the main content.
+    let content = aBrowser.contentWindow;
+
+    // Store the main content.
+    let scrolldata = ScrollPosition.collect(content) || {};
+
+    // Loop over direct child frames, and store the scroll positions.
+    let children = [];
+    for (let i = 0; i < content.frames.length; i++) {
+      let frame = content.frames[i];
+
+      let result = ScrollPosition.collect(frame);
+      if (result && Object.keys(result).length) {
+        children[i] = result;
+      }
+    }
+
+    // If any frame had scroll positions, add them to the main scroll data.
+    if (children.length) {
+      scrolldata.children = children;
+    }
+
+    // Save the current document resolution.
+    let zoom = { value: 1 };
+    content.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(
+      Ci.nsIDOMWindowUtils).getResolution(zoom);
+    scrolldata.zoom = {};
+    scrolldata.zoom.resolution = zoom.value;
+    log("onTabScroll() zoom level: " + zoom.value);
+
+    // Save some data that'll help in adjusting the zoom level
+    // when restoring in a different screen orientation.
+    scrolldata.zoom.displaySize = this._getContentViewerSize(content);
+    log("onTabScroll() displayWidth: " + scrolldata.zoom.displaySize.width);
+
+    // Save zoom and scroll data.
+    data.scrolldata = scrolldata;
+    log("onTabScroll() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id);
+    let evt = new Event("SSTabScrollCaptured", {"bubbles":true, "cancelable":false});
+    aBrowser.dispatchEvent(evt);
+    this.saveStateDelayed();
+  },
+
+  _getContentViewerSize: function ss_getContentViewerSize(aWindow) {
+    let displaySize = {};
+    let width = {}, height = {};
+    aWindow.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(
+      Ci.nsIDOMWindowUtils).getContentViewerSize(width, height);
+
+    displaySize.width = width.value;
+    displaySize.height = height.value;
+
+    return displaySize;
+  },
+
+  saveStateDelayed: function ss_saveStateDelayed() {
+    if (!this._saveTimer) {
+      // Interval until the next disk operation is allowed
+      let currentDelay = this._lastSaveTime + this._interval - Date.now();
+
+      // If we have to wait, set a timer, otherwise saveState directly
+      let delay = Math.max(currentDelay, this._minSaveDelay);
+      if (delay > 0) {
+        this._pendingWrite++;
+        this._saveTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+        this._saveTimer.init(this, delay, Ci.nsITimer.TYPE_ONE_SHOT);
+        log("saveStateDelayed() timer delay = " + delay +
+             ", incrementing _pendingWrite to " + this._pendingWrite);
+      } else {
+        log("saveStateDelayed() no delay");
+        this.saveState();
+      }
+    } else {
+      log("saveStateDelayed() timer already running, taking no action");
+    }
+  },
+
+  saveState: function ss_saveState() {
+    this._pendingWrite++;
+    log("saveState(), incrementing _pendingWrite to " + this._pendingWrite);
+    this._saveState(true);
+  },
+
+  // Immediately and synchronously writes any pending state to disk.
+  flushPendingState: function ss_flushPendingState() {
+    log("flushPendingState(), _pendingWrite = " + this._pendingWrite);
+    if (this._pendingWrite) {
+      this._saveState(false);
+    }
+  },
+
+  _saveState: function ss_saveState(aAsync) {
+    log("_saveState(aAsync = " + aAsync + ")");
+    // Kill any queued timer and save immediately
+    if (this._saveTimer) {
+      this._saveTimer.cancel();
+      this._saveTimer = null;
+      log("_saveState() killed queued timer");
+    }
+
+    // Periodically save a "known good" copy of the session store data.
+    if (!this._writeInProgress && Date.now() - this._lastBackupTime > this._backupInterval &&
+         this._sessionDataIsGood && this._sessionFile.exists()) {
+      if (this._sessionFileBackup.exists()) {
+        this._sessionFileBackup.remove(false);
+      }
+
+      log("_saveState() backing up session data");
+      this._sessionFile.copyTo(null, this._sessionFileBackup.leafName);
+      this._lastBackupTime = Date.now();
+    }
+
+    let data = this._getCurrentState();
+    let normalData = { windows: [] };
+    let privateData = { windows: [] };
+    log("_saveState() current state collected");
+
+    for (let winIndex = 0; winIndex < data.windows.length; ++winIndex) {
+      let win = data.windows[winIndex];
+      let normalWin = {};
+      for (let prop in win) {
+        normalWin[prop] = data[prop];
+      }
+      normalWin.tabs = [];
+
+      // Save normal closed tabs. Forget about private closed tabs.
+      normalWin.closedTabs = win.closedTabs.filter(tab => !tab.isPrivate);
+
+      normalData.windows.push(normalWin);
+      privateData.windows.push({ tabs: [] });
+
+      // Split the session data into private and non-private data objects.
+      // Non-private session data will be saved to disk, and private session
+      // data will be sent to Java for Android to hold it in memory.
+      for (let i = 0; i < win.tabs.length; ++i) {
+        let tab = win.tabs[i];
+        let savedWin = tab.isPrivate ? privateData.windows[winIndex] : normalData.windows[winIndex];
+        savedWin.tabs.push(tab);
+        if (win.selected == i + 1) {
+          savedWin.selected = savedWin.tabs.length;
+        }
+      }
+    }
+
+    // Write only non-private data to disk
+    if (normalData.windows[0] && normalData.windows[0].tabs) {
+      log("_saveState() writing normal data, " +
+           normalData.windows[0].tabs.length + " tabs in window[0]");
+    } else {
+      log("_saveState() writing empty normal data");
+    }
+    this._writeFile(this._sessionFile, this._sessionFileTemp, normalData, aAsync);
+
+    // If we have private data, send it to Java; otherwise, send null to
+    // indicate that there is no private data
+    Messaging.sendRequest({
+      type: "PrivateBrowsing:Data",
+      session: (privateData.windows.length > 0 && privateData.windows[0].tabs.length > 0) ? JSON.stringify(privateData) : null
+    });
+
+    this._lastSaveTime = Date.now();
+  },
+
+  _getCurrentState: function ss_getCurrentState() {
+    let self = this;
+    this._forEachBrowserWindow(function(aWindow) {
+      self._collectWindowData(aWindow);
+    });
+
+    let data = { windows: [] };
+    for (let index in this._windows) {
+      data.windows.push(this._windows[index]);
+    }
+
+    return data;
+  },
+
+  _collectTabData: function ss__collectTabData(aWindow, aBrowser, aHistory) {
+    // If this browser is being restored, skip any session save activity
+    if (aBrowser.__SS_restore) {
+      return;
+    }
+
+    aHistory = aHistory || { entries: [{ url: aBrowser.currentURI.spec, title: aBrowser.contentTitle }], index: 1 };
+
+    let tabData = {};
+    tabData.entries = aHistory.entries;
+    tabData.index = aHistory.index;
+    tabData.attributes = { image: aBrowser.mIconURL };
+    tabData.desktopMode = aWindow.BrowserApp.getTabForBrowser(aBrowser).desktopMode;
+    tabData.isPrivate = aBrowser.docShell.QueryInterface(Ci.nsILoadContext).usePrivateBrowsing;
+
+    aBrowser.__SS_data = tabData;
+  },
+
+  _collectWindowData: function ss__collectWindowData(aWindow) {
+    // Ignore windows not tracked by SessionStore
+    if (!aWindow.__SSID || !this._windows[aWindow.__SSID]) {
+      return;
+    }
+
+    let winData = this._windows[aWindow.__SSID];
+    winData.tabs = [];
+
+    let browsers = aWindow.document.getElementById("browsers");
+    let index = browsers.selectedIndex;
+    winData.selected = parseInt(index) + 1; // 1-based
+
+    let tabs = aWindow.BrowserApp.tabs;
+    for (let i = 0; i < tabs.length; i++) {
+      let browser = tabs[i].browser;
+      if (browser.__SS_data) {
+        let tabData = browser.__SS_data;
+        if (browser.__SS_extdata) {
+          tabData.extData = browser.__SS_extdata;
+        }
+        winData.tabs.push(tabData);
+      }
+    }
+  },
+
+  _forEachBrowserWindow: function ss_forEachBrowserWindow(aFunc) {
+    let windowsEnum = Services.wm.getEnumerator("navigator:browser");
+    while (windowsEnum.hasMoreElements()) {
+      let window = windowsEnum.getNext();
+      if (window.__SSID && !window.closed) {
+        aFunc.call(this, window);
+      }
+    }
+  },
+
+  /**
+   * Writes the session state to a disk file, while doing some telemetry and notification
+   * bookkeeping.
+   * @param aFile nsIFile used for saving the session
+   * @param aFileTemp nsIFile used as a temporary file in writing the data
+   * @param aData JSON session state
+   * @param aAsync boolelan used to determine the method of saving the state
+   */
+  _writeFile: function ss_writeFile(aFile, aFileTemp, aData, aAsync) {
+    TelemetryStopwatch.start("FX_SESSION_RESTORE_SERIALIZE_DATA_MS");
+    let state = JSON.stringify(aData);
+    TelemetryStopwatch.finish("FX_SESSION_RESTORE_SERIALIZE_DATA_MS");
+
+    // Convert data string to a utf-8 encoded array buffer
+    let buffer = new TextEncoder().encode(state);
+    Services.telemetry.getHistogramById("FX_SESSION_RESTORE_FILE_SIZE_BYTES").add(buffer.byteLength);
+
+    Services.obs.notifyObservers(null, "sessionstore-state-write", "");
+    let startWriteMs = Cu.now();
+
+    log("_writeFile(aAsync = " + aAsync + "), _pendingWrite = " + this._pendingWrite);
+    this._writeInProgress = true;
+    let pendingWrite = this._pendingWrite;
+    this._write(aFile, aFileTemp, buffer, aAsync).then(() => {
+      let stopWriteMs = Cu.now();
+
+      // Make sure this._pendingWrite is the same value it was before we
+      // fired off the async write. If the count is different, another write
+      // is pending, so we shouldn't reset this._pendingWrite yet.
+      if (pendingWrite === this._pendingWrite) {
+        this._pendingWrite = 0;
+        this._writeInProgress = false;
+      }
+
+      log("_writeFile() _write() returned, _pendingWrite = " + this._pendingWrite);
+
+      // We don't use a stopwatch here since the calls are async and stopwatches can only manage
+      // a single timer per histogram.
+      Services.telemetry.getHistogramById("FX_SESSION_RESTORE_WRITE_FILE_MS").add(Math.round(stopWriteMs - startWriteMs));
+      Services.obs.notifyObservers(null, "sessionstore-state-write-complete", "");
+      this._sessionDataIsGood = true;
+    });
+  },
+
+  /**
+   * Writes the session state to a disk file, using async or sync methods
+   * @param aFile nsIFile used for saving the session
+   * @param aFileTemp nsIFile used as a temporary file in writing the data
+   * @param aBuffer UTF-8 encoded ArrayBuffer of the session state
+   * @param aAsync boolelan used to determine the method of saving the state
+   * @return Promise that resolves when the file has been written
+   */
+  _write: function ss_write(aFile, aFileTemp, aBuffer, aAsync) {
+    // Use async file writer and just return it's promise
+    if (aAsync) {
+      log("_write() writing asynchronously");
+      return OS.File.writeAtomic(aFile.path, aBuffer, { tmpPath: aFileTemp.path });
+    }
+
+    // Convert buffer to an encoded string and sync write to disk
+    let bytes = String.fromCharCode.apply(null, new Uint16Array(aBuffer));
+    let stream = Cc["@mozilla.org/network/file-output-stream;1"].createInstance(Ci.nsIFileOutputStream);
+    stream.init(aFileTemp, 0x02 | 0x08 | 0x20, 0o666, 0);
+    stream.write(bytes, bytes.length);
+    stream.close();
+    // Mimic writeAtomic behaviour when tmpPath is set and write
+    // to a temp file which is then renamed at the end.
+    aFileTemp.renameTo(null, aFile.leafName);
+    log("_write() writing synchronously");
+
+    // Return a resolved promise to make the caller happy
+    return Promise.resolve();
+  },
+
+  _updateCrashReportURL: function ss_updateCrashReportURL(aWindow) {
+    let crashReporterBuilt = "nsICrashReporter" in Ci && Services.appinfo instanceof Ci.nsICrashReporter;
+    if (!crashReporterBuilt) {
+      return;
+    }
+
+    if (!aWindow.BrowserApp.selectedBrowser) {
+      return;
+    }
+
+    try {
+      let currentURI = aWindow.BrowserApp.selectedBrowser.currentURI.clone();
+      // if the current URI contains a username/password, remove it
+      try {
+        currentURI.userPass = "";
+      } catch (ex) { } // ignore failures on about: URIs
+
+      Services.appinfo.annotateCrashReport("URL", currentURI.spec);
+    } catch (ex) {
+      // don't make noise when crashreporter is built but not enabled
+      if (ex.result != Cr.NS_ERROR_NOT_INITIALIZED) {
+        Cu.reportError("SessionStore:" + ex);
+      }
+    }
+  },
+
+  /**
+   * Determines whether a given session history entry has been added dynamically.
+   */
+  isDynamic: function(aEntry) {
+    // aEntry.isDynamicallyAdded() is true for dynamically added
+    // <iframe> and <frameset>, but also for <html> (the root of the
+    // document) so we use aEntry.parent to ensure that we're not looking
+    // at the root of the document
+    return aEntry.parent && aEntry.isDynamicallyAdded();
+  },
+
+  /**
+  * Get an object that is a serialized representation of a History entry.
+  */
+  _serializeHistoryEntry: function _serializeHistoryEntry(aEntry) {
+    let entry = { url: aEntry.URI.spec };
+
+    if (aEntry.title && aEntry.title != entry.url) {
+      entry.title = aEntry.title;
+    }
+
+    if (!(aEntry instanceof Ci.nsISHEntry)) {
+      return entry;
+    }
+
+    let cacheKey = aEntry.cacheKey;
+    if (cacheKey && cacheKey instanceof Ci.nsISupportsPRUint32 && cacheKey.data != 0) {
+      entry.cacheKey = cacheKey.data;
+    }
+
+    entry.ID = aEntry.ID;
+    entry.docshellID = aEntry.docshellID;
+
+    if (aEntry.referrerURI) {
+      entry.referrer = aEntry.referrerURI.spec;
+    }
+
+    if (aEntry.originalURI) {
+      entry.originalURI = aEntry.originalURI.spec;
+    }
+
+    if (aEntry.loadReplace) {
+      entry.loadReplace = aEntry.loadReplace;
+    }
+
+    if (aEntry.contentType) {
+      entry.contentType = aEntry.contentType;
+    }
+
+    if (aEntry.scrollRestorationIsManual) {
+      entry.scrollRestorationIsManual = true;
+    } else {
+      let x = {}, y = {};
+      aEntry.getScrollPosition(x, y);
+      if (x.value != 0 || y.value != 0) {
+        entry.scroll = x.value + "," + y.value;
+      }
+    }
+
+    // Collect triggeringPrincipal data for the current history entry.
+    // Please note that before Bug 1297338 there was no concept of a
+    // principalToInherit. To remain backward/forward compatible we
+    // serialize the principalToInherit as triggeringPrincipal_b64.
+    // Once principalToInherit is well established (within FF55)
+    // we can update this code, remove triggeringPrincipal_b64 and
+    // just keep triggeringPrincipal_base64 as well as
+    // principalToInherit_base64;  see Bug 1301666.
+    if (aEntry.principalToInherit) {
+      try {
+        let principalToInherit = Utils.serializePrincipal(aEntry.principalToInherit);
+        if (principalToInherit) {
+          entry.triggeringPrincipal_b64 = principalToInherit;
+          entry.principalToInherit_base64 = principalToInherit;
+        }
+      } catch (e) {
+        dump(e);
+      }
+    }
+
+    if (aEntry.triggeringPrincipal) {
+      try {
+        let triggeringPrincipal = Utils.serializePrincipal(aEntry.triggeringPrincipal);
+        if (triggeringPrincipal) {
+          entry.triggeringPrincipal_base64 = triggeringPrincipal;
+        }
+      } catch (e) {
+        dump(e);
+      }
+    }
+
+    entry.docIdentifier = aEntry.BFCacheEntry.ID;
+
+    if (aEntry.stateData != null) {
+      entry.structuredCloneState = aEntry.stateData.getDataAsBase64();
+      entry.structuredCloneVersion = aEntry.stateData.formatVersion;
+    }
+
+    if (!(aEntry instanceof Ci.nsISHContainer)) {
+      return entry;
+    }
+
+    if (aEntry.childCount > 0) {
+      let children = [];
+      for (let i = 0; i < aEntry.childCount; i++) {
+        let child = aEntry.GetChildAt(i);
+
+        if (child && !this.isDynamic(child)) {
+          // don't try to restore framesets containing wyciwyg URLs (cf. bug 424689 and bug 450595)
+          if (child.URI.schemeIs("wyciwyg")) {
+            children = [];
+            break;
+          }
+          children.push(this._serializeHistoryEntry(child));
+        }
+      }
+
+      if (children.length) {
+        entry.children = children;
+      }
+    }
+
+    return entry;
+  },
+
+  _deserializeHistoryEntry: function _deserializeHistoryEntry(aEntry, aIdMap, aDocIdentMap) {
+    let shEntry = Cc["@mozilla.org/browser/session-history-entry;1"].createInstance(Ci.nsISHEntry);
+
+    shEntry.setURI(Services.io.newURI(aEntry.url, null, null));
+    shEntry.setTitle(aEntry.title || aEntry.url);
+    if (aEntry.subframe) {
+      shEntry.setIsSubFrame(aEntry.subframe || false);
+    }
+    shEntry.loadType = Ci.nsIDocShellLoadInfo.loadHistory;
+    if (aEntry.contentType) {
+      shEntry.contentType = aEntry.contentType;
+    }
+    if (aEntry.referrer) {
+      shEntry.referrerURI = Services.io.newURI(aEntry.referrer, null, null);
+    }
+
+    if (aEntry.originalURI) {
+      shEntry.originalURI =  Services.io.newURI(aEntry.originalURI, null, null);
+    }
+
+    if (aEntry.loadReplace) {
+      shEntry.loadReplace = aEntry.loadReplace;
+    }
+
+    if (aEntry.cacheKey) {
+      let cacheKey = Cc["@mozilla.org/supports-PRUint32;1"].createInstance(Ci.nsISupportsPRUint32);
+      cacheKey.data = aEntry.cacheKey;
+      shEntry.cacheKey = cacheKey;
+    }
+
+    if (aEntry.ID) {
+      // get a new unique ID for this frame (since the one from the last
+      // start might already be in use)
+      let id = aIdMap[aEntry.ID] || 0;
+      if (!id) {
+        for (id = Date.now(); id in aIdMap.used; id++);
+        aIdMap[aEntry.ID] = id;
+        aIdMap.used[id] = true;
+      }
+      shEntry.ID = id;
+    }
+
+    if (aEntry.docshellID) {
+      shEntry.docshellID = aEntry.docshellID;
+    }
+
+    if (aEntry.structuredCloneState && aEntry.structuredCloneVersion) {
+      shEntry.stateData =
+        Cc["@mozilla.org/docshell/structured-clone-container;1"].
+        createInstance(Ci.nsIStructuredCloneContainer);
+
+      shEntry.stateData.initFromBase64(aEntry.structuredCloneState, aEntry.structuredCloneVersion);
+    }
+
+    if (aEntry.scrollRestorationIsManual) {
+      shEntry.scrollRestorationIsManual = true;
+    } else if (aEntry.scroll) {
+      let scrollPos = aEntry.scroll.split(",");
+      scrollPos = [parseInt(scrollPos[0]) || 0, parseInt(scrollPos[1]) || 0];
+      shEntry.setScrollPosition(scrollPos[0], scrollPos[1]);
+    }
+
+    let childDocIdents = {};
+    if (aEntry.docIdentifier) {
+      // If we have a serialized document identifier, try to find an SHEntry
+      // which matches that doc identifier and adopt that SHEntry's
+      // BFCacheEntry.  If we don't find a match, insert shEntry as the match
+      // for the document identifier.
+      let matchingEntry = aDocIdentMap[aEntry.docIdentifier];
+      if (!matchingEntry) {
+        matchingEntry = {shEntry: shEntry, childDocIdents: childDocIdents};
+        aDocIdentMap[aEntry.docIdentifier] = matchingEntry;
+      } else {
+        shEntry.adoptBFCacheEntry(matchingEntry.shEntry);
+        childDocIdents = matchingEntry.childDocIdents;
+      }
+    }
+
+    // The field aEntry.owner_b64 got renamed to aEntry.triggeringPricipal_b64 in
+    // Bug 1286472. To remain backward compatible we still have to support that
+    // field for a few cycles before we can remove it within Bug 1289785.
+    if (aEntry.owner_b64) {
+      aEntry.triggeringPricipal_b64 = aEntry.owner_b64;
+      delete aEntry.owner_b64;
+    }
+
+    // Before introducing the concept of principalToInherit we only had
+    // a triggeringPrincipal within every entry which basically is the
+    // equivalent of the new principalToInherit. To avoid compatibility
+    // issues, we first check if the entry has entries for
+    // triggeringPrincipal_base64 and principalToInherit_base64. If not
+    // we fall back to using the principalToInherit (which is stored
+    // as triggeringPrincipal_b64) as the triggeringPrincipal and
+    // the principalToInherit.
+    // FF55 will remove the triggeringPrincipal_b64, see Bug 1301666.
+    if (aEntry.triggeringPrincipal_base64 || aEntry.principalToInherit_base64) {
+      if (aEntry.triggeringPrincipal_base64) {
+        shEntry.triggeringPrincipal =
+          Utils.deserializePrincipal(aEntry.triggeringPrincipal_base64);
+      }
+      if (aEntry.principalToInherit_base64) {
+        shEntry.principalToInherit =
+          Utils.deserializePrincipal(aEntry.principalToInherit_base64);
+      }
+    } else if (aEntry.triggeringPrincipal_b64) {
+      shEntry.triggeringPrincipal = Utils.deserializePrincipal(aEntry.triggeringPrincipal_b64);
+      shEntry.principalToInherit = shEntry.triggeringPrincipal;
+    }
+
+    if (aEntry.children && shEntry instanceof Ci.nsISHContainer) {
+      for (let i = 0; i < aEntry.children.length; i++) {
+        if (!aEntry.children[i].url) {
+          continue;
+        }
+
+        // We're getting sessionrestore.js files with a cycle in the
+        // doc-identifier graph, likely due to bug 698656.  (That is, we have
+        // an entry where doc identifier A is an ancestor of doc identifier B,
+        // and another entry where doc identifier B is an ancestor of A.)
+        //
+        // If we were to respect these doc identifiers, we'd create a cycle in
+        // the SHEntries themselves, which causes the docshell to loop forever
+        // when it looks for the root SHEntry.
+        //
+        // So as a hack to fix this, we restrict the scope of a doc identifier
+        // to be a node's siblings and cousins, and pass childDocIdents, not
+        // aDocIdents, to _deserializeHistoryEntry.  That is, we say that two
+        // SHEntries with the same doc identifier have the same document iff
+        // they have the same parent or their parents have the same document.
+
+        shEntry.AddChild(this._deserializeHistoryEntry(aEntry.children[i], aIdMap, childDocIdents), i);
+      }
+    }
+
+    return shEntry;
+  },
+
+  // This function iterates through a list of urls opening a new tab for each.
+  _openTabs: function ss_openTabs(aData) {
+    let window = Services.wm.getMostRecentWindow("navigator:browser");
+    for (let i = 0; i < aData.urls.length; i++) {
+      let url = aData.urls[i];
+      let params = {
+        selected: (i == aData.urls.length - 1),
+        isPrivate: false,
+        desktopMode: false,
+      };
+
+      let tab = window.BrowserApp.addTab(url, params);
+    }
+  },
+
+  // This function iterates through a list of tab data restoring session for each of them.
+  _restoreTabs: function ss_restoreTabs(aData) {
+    let window = Services.wm.getMostRecentWindow("navigator:browser");
+    for (let i = 0; i < aData.tabs.length; i++) {
+      let tabData = JSON.parse(aData.tabs[i]);
+      let isSelectedTab = (i == aData.tabs.length - 1);
+      let params = {
+        selected: isSelectedTab,
+        isPrivate: tabData.isPrivate,
+        desktopMode: tabData.desktopMode,
+        cancelEditMode: isSelectedTab
+      };
+
+      let tab = window.BrowserApp.addTab(tabData.entries[tabData.index - 1].url, params);
+      tab.browser.__SS_data = tabData;
+      tab.browser.__SS_extdata = tabData.extData;
+      this._restoreTab(tabData, tab.browser);
+    }
+  },
+
+  /**
+   * Don't save sensitive data if the user doesn't want to
+   * (distinguishes between encrypted and non-encrypted sites)
+   */
+  checkPrivacyLevel: function ss_checkPrivacyLevel(aURL) {
+    let isHTTPS = aURL.startsWith("https:");
+    let pref = "browser.sessionstore.privacy_level";
+    return Services.prefs.getIntPref(pref) < (isHTTPS ? PRIVACY_ENCRYPTED : PRIVACY_FULL);
+  },
+
+  /**
+  * Starts the restoration process for a browser. History is restored at this
+  * point, but text data must be delayed until the content loads.
+  */
+  _restoreTab: function ss_restoreTab(aTabData, aBrowser) {
+    // aTabData shouldn't be empty here, but if it is,
+    // _restoreHistory() will crash otherwise.
+    if (!aTabData || aTabData.entries.length == 0) {
+      Cu.reportError("SessionStore.js: Error trying to restore tab with empty tabdata");
+      return;
+    }
+    this._restoreHistory(aTabData, aBrowser.sessionHistory);
+
+    // Various bits of state can only be restored if page loading has progressed far enough:
+    // The MobileViewportManager needs to be told as early as possible about
+    // our desired zoom level so it can take it into account during the
+    // initial document resolution calculation.
+    aBrowser.__SS_restoreDataOnLocationChange = true;
+    // Restoring saved form data requires the input fields to be available,
+    // so we have to wait for the content to load.
+    aBrowser.__SS_restoreDataOnLoad = true;
+    // Restoring the scroll position depends on the document resolution having been set,
+    // which is only guaranteed to have happened *after* we receive the load event.
+    aBrowser.__SS_restoreDataOnPageshow = true;
+  },
+
+  /**
+  * Takes serialized history data and create news entries into the given
+  * nsISessionHistory object.
+  */
+  _restoreHistory: function ss_restoreHistory(aTabData, aHistory) {
+    if (aHistory.count > 0) {
+      aHistory.PurgeHistory(aHistory.count);
+    }
+    aHistory.QueryInterface(Ci.nsISHistoryInternal);
+
+    // Helper hashes for ensuring unique frame IDs and unique document
+    // identifiers.
+    let idMap = { used: {} };
+    let docIdentMap = {};
+
+    for (let i = 0; i < aTabData.entries.length; i++) {
+      if (!aTabData.entries[i].url) {
+        continue;
+      }
+      aHistory.addEntry(this._deserializeHistoryEntry(aTabData.entries[i], idMap, docIdentMap), true);
+    }
+
+    // We need to force set the active history item and cause it to reload since
+    // we stop the load above
+    let activeIndex = (aTabData.index || aTabData.entries.length) - 1;
+    aHistory.getEntryAtIndex(activeIndex, true);
+
+    try {
+      aHistory.QueryInterface(Ci.nsISHistory).reloadCurrentEntry();
+    } catch (e) {
+      // This will throw if the current entry is an error page.
+    }
+  },
+
+  /**
+  * Takes serialized form text data and restores it into the given browser.
+  */
+  _restoreTextData: function ss_restoreTextData(aFormData, aBrowser) {
+    if (aFormData) {
+      log("_restoreTextData()");
+      FormData.restoreTree(aBrowser.contentWindow, aFormData);
+    }
+  },
+
+  /**
+   * Restores the zoom level of the window. This needs to be called before
+   * first paint/load (whichever comes first) to take any effect.
+   */
+  _restoreZoom: function ss_restoreZoom(aScrollData, aBrowser) {
+    if (aScrollData && aScrollData.zoom && aScrollData.zoom.displaySize) {
+      log("_restoreZoom(), resolution: " + aScrollData.zoom.resolution +
+          ", old displayWidth: " + aScrollData.zoom.displaySize.width);
+
+      let utils = aBrowser.contentWindow.QueryInterface(
+        Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
+      // Restore zoom level.
+      utils.setRestoreResolution(aScrollData.zoom.resolution,
+                                 aScrollData.zoom.displaySize.width,
+                                 aScrollData.zoom.displaySize.height);
+    }
+  },
+
+  /**
+  * Takes serialized scroll positions and restores them into the given browser.
+  */
+  _restoreScrollPosition: function ss_restoreScrollPosition(aScrollData, aBrowser) {
+    if (aScrollData) {
+      log("_restoreScrollPosition()");
+      ScrollPosition.restoreTree(aBrowser.contentWindow, aScrollData);
+    }
+  },
+
+  getBrowserState: function ss_getBrowserState() {
+    return this._getCurrentState();
+  },
+
+  _restoreWindow: function ss_restoreWindow(aData) {
+    let state;
+    try {
+      state = JSON.parse(aData);
+    } catch (e) {
+      throw "Invalid session JSON: " + aData;
+    }
+
+    // To do a restore, we must have at least one window with one tab
+    if (!state || state.windows.length == 0 || !state.windows[0].tabs || state.windows[0].tabs.length == 0) {
+      throw "Invalid session JSON: " + aData;
+    }
+
+    let window = Services.wm.getMostRecentWindow("navigator:browser");
+
+    let tabs = state.windows[0].tabs;
+    let selected = state.windows[0].selected;
+    log("_restoreWindow() selected tab in aData is " + selected + " of " + tabs.length)
+    if (selected == null || selected > tabs.length) { // Clamp the selected index if it's bogus
+      log("_restoreWindow() resetting selected tab");
+      selected = 1;
+    }
+    log("restoreWindow() window.BrowserApp.selectedTab is " + window.BrowserApp.selectedTab.id);
+
+    for (let i = 0; i < tabs.length; i++) {
+      let tabData = tabs[i];
+      let entry = tabData.entries[tabData.index - 1];
+
+      // Use stubbed tab if we've already created it; otherwise, make a new tab
+      let tab;
+      if (tabData.tabId == null) {
+        let params = {
+          selected: (selected == i+1),
+          delayLoad: true,
+          title: entry.title,
+          desktopMode: (tabData.desktopMode == true),
+          isPrivate: (tabData.isPrivate == true)
+        };
+        tab = window.BrowserApp.addTab(entry.url, params);
+      } else {
+        tab = window.BrowserApp.getTabForId(tabData.tabId);
+        delete tabData.tabId;
+
+        // Don't restore tab if user has closed it
+        if (tab == null) {
+          continue;
+        }
+      }
+
+      tab.browser.__SS_data = tabData;
+      tab.browser.__SS_extdata = tabData.extData;
+
+      if (window.BrowserApp.selectedTab == tab) {
+        this._restoreTab(tabData, tab.browser);
+
+        // We can now lift the general ban on tab data capturing,
+        // but we still need to protect the foreground tab until we're
+        // sure it's actually reloading after history restoring has finished.
+        tab.browser.__SS_restoreReloadPending = true;
+        this._startupRestoreFinished = true;
+        log("startupRestoreFinished = true");
+
+        delete tab.browser.__SS_restore;
+        tab.browser.removeAttribute("pending");
+      } else {
+        // Mark the browser for delay loading
+        tab.browser.__SS_restore = true;
+        tab.browser.setAttribute("pending", "true");
+      }
+    }
+
+    // Restore the closed tabs array on the current window.
+    if (state.windows[0].closedTabs) {
+      this._windows[window.__SSID].closedTabs = state.windows[0].closedTabs;
+      log("_restoreWindow() loaded " + state.windows[0].closedTabs.length + " closed tabs");
+    }
+  },
+
+  getClosedTabCount: function ss_getClosedTabCount(aWindow) {
+    if (!aWindow || !aWindow.__SSID || !this._windows[aWindow.__SSID]) {
+      return 0; // not a browser window, or not otherwise tracked by SS.
+    }
+
+    return this._windows[aWindow.__SSID].closedTabs.length;
+  },
+
+  getClosedTabs: function ss_getClosedTabs(aWindow) {
+    if (!aWindow.__SSID) {
+      throw (Components.returnCode = Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    return this._windows[aWindow.__SSID].closedTabs;
+  },
+
+  undoCloseTab: function ss_undoCloseTab(aWindow, aCloseTabData) {
+    if (!aWindow.__SSID) {
+      throw (Components.returnCode = Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    let closedTabs = this._windows[aWindow.__SSID].closedTabs;
+    if (!closedTabs) {
+      return null;
+    }
+
+    // If the tab data is in the closedTabs array, remove it.
+    closedTabs.find(function (tabData, i) {
+      if (tabData == aCloseTabData) {
+        closedTabs.splice(i, 1);
+        return true;
+      }
+    });
+
+    // create a new tab and bring to front
+    let params = {
+      selected: true,
+      isPrivate: aCloseTabData.isPrivate,
+      desktopMode: aCloseTabData.desktopMode,
+      tabIndex: this._lastClosedTabIndex
+    };
+    let tab = aWindow.BrowserApp.addTab(aCloseTabData.entries[aCloseTabData.index - 1].url, params);
+    tab.browser.__SS_data = aCloseTabData;
+    tab.browser.__SS_extdata = aCloseTabData.extData;
+    this._restoreTab(aCloseTabData, tab.browser);
+
+    this._lastClosedTabIndex = -1;
+
+    if (this._notifyClosedTabs) {
+      this._sendClosedTabsToJava(aWindow);
+    }
+
+    return tab.browser;
+  },
+
+  forgetClosedTab: function ss_forgetClosedTab(aWindow, aIndex) {
+    if (!aWindow.__SSID) {
+      throw (Components.returnCode = Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    let closedTabs = this._windows[aWindow.__SSID].closedTabs;
+
+    // default to the most-recently closed tab
+    aIndex = aIndex || 0;
+    if (!(aIndex in closedTabs)) {
+      throw (Components.returnCode = Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    // remove closed tab from the array
+    closedTabs.splice(aIndex, 1);
+
+    // Forget the last closed tab index if we're forgetting the last closed tab.
+    if (aIndex == 0) {
+      this._lastClosedTabIndex = -1;
+    }
+    if (this._notifyClosedTabs) {
+      this._sendClosedTabsToJava(aWindow);
+    }
+  },
+
+  _sendClosedTabsToJava: function ss_sendClosedTabsToJava(aWindow) {
+    if (!aWindow.__SSID) {
+      throw (Components.returnCode = Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    let closedTabs = this._windows[aWindow.__SSID].closedTabs;
+    let isPrivate = PrivateBrowsingUtils.isBrowserPrivate(aWindow.BrowserApp.selectedBrowser);
+
+    let tabs = closedTabs
+      .filter(tab => tab.isPrivate == isPrivate)
+      .map(function (tab) {
+        // Get the url and title for the last entry in the session history.
+        let lastEntry = tab.entries[tab.entries.length - 1];
+        return {
+          url: lastEntry.url,
+          title: lastEntry.title || "",
+          data: tab
+        };
+      });
+
+    log("sending " + tabs.length + " closed tabs to Java");
+    Messaging.sendRequest({
+      type: "ClosedTabs:Data",
+      tabs: tabs
+    });
+  },
+
+  getTabValue: function ss_getTabValue(aTab, aKey) {
+    let browser = aTab.browser;
+    let data = browser.__SS_extdata || {};
+    return data[aKey] || "";
+  },
+
+  setTabValue: function ss_setTabValue(aTab, aKey, aStringValue) {
+    let browser = aTab.browser;
+    if (!browser.__SS_extdata) {
+      browser.__SS_extdata = {};
+    }
+    browser.__SS_extdata[aKey] = aStringValue;
+    this.saveStateDelayed();
+  },
+
+  deleteTabValue: function ss_deleteTabValue(aTab, aKey) {
+    let browser = aTab.browser;
+    if (browser.__SS_extdata && aKey in browser.__SS_extdata) {
+      delete browser.__SS_extdata[aKey];
+      this.saveStateDelayed();
+    }
+  },
+
+  restoreLastSession: Task.async(function* (aSessionString) {
+    let notifyMessage = "";
+
+    try {
+      this._restoreWindow(aSessionString);
+    } catch (e) {
+      Cu.reportError("SessionStore: " + e);
+      notifyMessage = "fail";
+    }
+
+    Services.obs.notifyObservers(null, "sessionstore-windows-restored", notifyMessage);
+  }),
+
+  removeWindow: function ss_removeWindow(aWindow) {
+    if (!aWindow || !aWindow.__SSID || !this._windows[aWindow.__SSID]) {
+      return;
+    }
+
+    delete this._windows[aWindow.__SSID];
+    delete aWindow.__SSID;
+
+    if (this._loadState == STATE_RUNNING) {
+      // Save the purged state immediately
+      this.saveState();
+    } else if (this._loadState <= STATE_QUITTING) {
+      this.saveStateDelayed();
+    }
+  }
+
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([SessionStore]);