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			1500 lines
		
	
	
	
		
			46 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			1500 lines
		
	
	
	
		
			46 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
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 * This Source Code Form is subject to the terms of the Mozilla Public
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 * License, v. 2.0. If a copy of the MPL was not distributed with this
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 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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"use strict";
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var EXPORTED_SYMBOLS = ["AsyncTabSwitcher"];
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const { XPCOMUtils } = ChromeUtils.importESModule(
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  "resource://gre/modules/XPCOMUtils.sys.mjs"
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);
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const { AppConstants } = ChromeUtils.importESModule(
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  "resource://gre/modules/AppConstants.sys.mjs"
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);
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const lazy = {};
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ChromeUtils.defineESModuleGetters(lazy, {
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  PictureInPicture: "resource://gre/modules/PictureInPicture.sys.mjs",
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});
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XPCOMUtils.defineLazyPreferenceGetter(
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  lazy,
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  "gTabWarmingEnabled",
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  "browser.tabs.remote.warmup.enabled"
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);
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XPCOMUtils.defineLazyPreferenceGetter(
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  lazy,
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  "gTabWarmingMax",
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  "browser.tabs.remote.warmup.maxTabs"
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);
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XPCOMUtils.defineLazyPreferenceGetter(
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  lazy,
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  "gTabWarmingUnloadDelayMs",
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  "browser.tabs.remote.warmup.unloadDelayMs"
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);
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XPCOMUtils.defineLazyPreferenceGetter(
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  lazy,
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  "gTabCacheSize",
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  "browser.tabs.remote.tabCacheSize"
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);
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/**
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 * The tab switcher is responsible for asynchronously switching
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 * tabs in e10s. It waits until the new tab is ready (i.e., the
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 * layer tree is available) before switching to it. Then it
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 * unloads the layer tree for the old tab.
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 *
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 * The tab switcher is a state machine. For each tab, it
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 * maintains state about whether the layer tree for the tab is
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 * available, being loaded, being unloaded, or unavailable. It
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 * also keeps track of the tab currently being displayed, the tab
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 * it's trying to load, and the tab the user has asked to switch
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 * to. The switcher object is created upon tab switch. It is
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 * released when there are no pending tabs to load or unload.
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 *
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 * The following general principles have guided the design:
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 *
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 * 1. We only request one layer tree at a time. If the user
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 * switches to a different tab while waiting, we don't request
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 * the new layer tree until the old tab has loaded or timed out.
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 *
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 * 2. If loading the layers for a tab times out, we show the
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 * spinner and possibly request the layer tree for another tab if
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 * the user has requested one.
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 *
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 * 3. We discard layer trees on a delay. This way, if the user is
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 * switching among the same tabs frequently, we don't continually
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 * load the same tabs.
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 *
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 * It's important that we always show either the spinner or a tab
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 * whose layers are available. Otherwise the compositor will draw
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 * an entirely black frame, which is very jarring. To ensure this
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 * never happens when switching away from a tab, we assume the
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 * old tab might still be drawn until a MozAfterPaint event
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 * occurs. Because layout and compositing happen asynchronously,
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 * we don't have any other way of knowing when the switch
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 * actually takes place. Therefore, we don't unload the old tab
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 * until the next MozAfterPaint event.
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 */
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class AsyncTabSwitcher {
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  constructor(tabbrowser) {
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    this.log("START");
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    // How long to wait for a tab's layers to load. After this
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    // time elapses, we're free to put up the spinner and start
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    // trying to load a different tab.
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    this.TAB_SWITCH_TIMEOUT = 400; // ms
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    // When the user hasn't switched tabs for this long, we unload
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    // layers for all tabs that aren't in use.
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    this.UNLOAD_DELAY = 300; // ms
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    // The next three tabs form the principal state variables.
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    // See the assertions in postActions for their invariants.
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    // Tab the user requested most recently.
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    this.requestedTab = tabbrowser.selectedTab;
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    // Tab we're currently trying to load.
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    this.loadingTab = null;
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    // We show this tab in case the requestedTab hasn't loaded yet.
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    this.lastVisibleTab = tabbrowser.selectedTab;
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    // Auxilliary state variables:
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    this.visibleTab = tabbrowser.selectedTab; // Tab that's on screen.
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    this.spinnerTab = null; // Tab showing a spinner.
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    this.blankTab = null; // Tab showing blank.
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    this.lastPrimaryTab = tabbrowser.selectedTab; // Tab with primary="true"
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    this.tabbrowser = tabbrowser;
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    this.window = tabbrowser.ownerGlobal;
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    this.loadTimer = null; // TAB_SWITCH_TIMEOUT nsITimer instance.
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    this.unloadTimer = null; // UNLOAD_DELAY nsITimer instance.
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    // Map from tabs to STATE_* (below).
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    this.tabState = new Map();
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    // True if we're in the midst of switching tabs.
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    this.switchInProgress = false;
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    // Transaction id for the composite that will show the requested
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    // tab for the first tab after a tab switch.
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    // Set to -1 when we're not waiting for notification of a
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    // completed switch.
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    this.switchPaintId = -1;
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    // Set of tabs that might be visible right now. We maintain
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    // this set because we can't be sure when a tab is actually
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    // drawn. A tab is added to this set when we ask to make it
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    // visible. All tabs but the most recently shown tab are
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    // removed from the set upon MozAfterPaint.
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    this.maybeVisibleTabs = new Set([tabbrowser.selectedTab]);
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    // This holds onto the set of tabs that we've been asked to warm up,
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    // and tabs are evicted once they're done loading or are unloaded.
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    this.warmingTabs = new WeakSet();
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    this.STATE_UNLOADED = 0;
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    this.STATE_LOADING = 1;
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    this.STATE_LOADED = 2;
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    this.STATE_UNLOADING = 3;
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    // re-entrancy guard:
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    this._processing = false;
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    // For telemetry, keeps track of what most recently cleared
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    // the loadTimer, which can tell us something about the cause
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    // of tab switch spinners.
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    this._loadTimerClearedBy = "none";
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    this._useDumpForLogging = false;
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    this._logInit = false;
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    this._logFlags = [];
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    this.window.addEventListener("MozAfterPaint", this);
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    this.window.addEventListener("MozLayerTreeReady", this);
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    this.window.addEventListener("MozLayerTreeCleared", this);
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    this.window.addEventListener("TabRemotenessChange", this);
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    this.window.addEventListener("SwapDocShells", this, true);
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    this.window.addEventListener("EndSwapDocShells", this, true);
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    this.window.document.addEventListener("visibilitychange", this);
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    let initialTab = this.requestedTab;
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    let initialBrowser = initialTab.linkedBrowser;
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    let tabIsLoaded =
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      !initialBrowser.isRemoteBrowser ||
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      initialBrowser.frameLoader.remoteTab?.hasLayers;
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    // If we minimized the window before the switcher was activated,
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    // we might have set  the preserveLayers flag for the current
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    // browser. Let's clear it.
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    initialBrowser.preserveLayers(false);
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    if (!this.windowHidden) {
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      this.log("Initial tab is loaded?: " + tabIsLoaded);
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      this.setTabState(
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        initialTab,
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        tabIsLoaded ? this.STATE_LOADED : this.STATE_LOADING
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      );
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    }
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    for (let ppBrowser of this.tabbrowser._printPreviewBrowsers) {
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      let ppTab = this.tabbrowser.getTabForBrowser(ppBrowser);
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      let state = ppBrowser.hasLayers ? this.STATE_LOADED : this.STATE_LOADING;
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      this.setTabState(ppTab, state);
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    }
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  }
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  destroy() {
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    if (this.unloadTimer) {
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      this.clearTimer(this.unloadTimer);
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      this.unloadTimer = null;
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    }
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    if (this.loadTimer) {
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      this.clearTimer(this.loadTimer);
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      this.loadTimer = null;
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    }
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    this.window.removeEventListener("MozAfterPaint", this);
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    this.window.removeEventListener("MozLayerTreeReady", this);
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    this.window.removeEventListener("MozLayerTreeCleared", this);
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    this.window.removeEventListener("TabRemotenessChange", this);
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    this.window.removeEventListener("SwapDocShells", this, true);
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    this.window.removeEventListener("EndSwapDocShells", this, true);
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    this.window.document.removeEventListener("visibilitychange", this);
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    this.tabbrowser._switcher = null;
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  }
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  // Wraps nsITimer. Must not use the vanilla setTimeout and
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  // clearTimeout, because they will be blocked by nsIPromptService
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  // dialogs.
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  setTimer(callback, timeout) {
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    let event = {
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      notify: callback,
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    };
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    var timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
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    timer.initWithCallback(event, timeout, Ci.nsITimer.TYPE_ONE_SHOT);
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    return timer;
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  }
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  clearTimer(timer) {
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    timer.cancel();
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  }
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  getTabState(tab) {
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    let state = this.tabState.get(tab);
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    // As an optimization, we lazily evaluate the state of tabs
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    // that we've never seen before. Once we've figured it out,
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    // we stash it in our state map.
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    if (state === undefined) {
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      state = this.STATE_UNLOADED;
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      if (tab && tab.linkedPanel) {
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        let b = tab.linkedBrowser;
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        if (b.renderLayers && b.hasLayers) {
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          state = this.STATE_LOADED;
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        } else if (b.renderLayers && !b.hasLayers) {
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          state = this.STATE_LOADING;
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        } else if (!b.renderLayers && b.hasLayers) {
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          state = this.STATE_UNLOADING;
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        }
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      }
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      this.setTabStateNoAction(tab, state);
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    }
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    return state;
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  }
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  setTabStateNoAction(tab, state) {
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    if (state == this.STATE_UNLOADED) {
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      this.tabState.delete(tab);
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    } else {
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      this.tabState.set(tab, state);
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    }
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  }
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  setTabState(tab, state) {
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    if (state == this.getTabState(tab)) {
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      return;
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    }
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    this.setTabStateNoAction(tab, state);
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    let browser = tab.linkedBrowser;
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    let { remoteTab } = browser.frameLoader;
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    if (state == this.STATE_LOADING) {
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      this.assert(!this.windowHidden);
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      // If we're not in the process of warming this tab, we
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      // don't need to delay activating its DocShell.
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      if (!this.warmingTabs.has(tab)) {
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        browser.docShellIsActive = true;
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      }
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      if (remoteTab) {
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        browser.renderLayers = true;
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        remoteTab.priorityHint = true;
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      } else {
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        this.onLayersReady(browser);
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      }
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    } else if (state == this.STATE_UNLOADING) {
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      this.unwarmTab(tab);
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      // Setting the docShell to be inactive will also cause it
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      // to stop rendering layers.
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      browser.docShellIsActive = false;
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      if (remoteTab) {
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        remoteTab.priorityHint = false;
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      } else {
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        this.onLayersCleared(browser);
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      }
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    } else if (state == this.STATE_LOADED) {
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      this.maybeActivateDocShell(tab);
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    }
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    if (!tab.linkedBrowser.isRemoteBrowser) {
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      // setTabState is potentially re-entrant in the non-remote case,
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      // so we must re-get the state for this assertion.
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      let nonRemoteState = this.getTabState(tab);
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      // Non-remote tabs can never stay in the STATE_LOADING
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      // or STATE_UNLOADING states. By the time this function
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      // exits, a non-remote tab must be in STATE_LOADED or
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      // STATE_UNLOADED, since the painting and the layer
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      // upload happen synchronously.
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      this.assert(
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        nonRemoteState == this.STATE_UNLOADED ||
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          nonRemoteState == this.STATE_LOADED
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      );
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    }
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  }
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  get windowHidden() {
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    return this.window.document.hidden;
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  }
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  get tabLayerCache() {
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    return this.tabbrowser._tabLayerCache;
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  }
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  finish() {
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    this.log("FINISH");
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    this.assert(this.tabbrowser._switcher);
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    this.assert(this.tabbrowser._switcher === this);
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    this.assert(!this.spinnerTab);
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    this.assert(!this.blankTab);
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    this.assert(!this.loadTimer);
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    this.assert(!this.loadingTab);
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    this.assert(this.lastVisibleTab === this.requestedTab);
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    this.assert(
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      this.windowHidden ||
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        this.getTabState(this.requestedTab) == this.STATE_LOADED
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    );
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    this.destroy();
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    this.window.document.commandDispatcher.unlock();
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    let event = new this.window.CustomEvent("TabSwitchDone", {
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      bubbles: true,
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      cancelable: true,
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    });
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    this.tabbrowser.dispatchEvent(event);
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  }
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  // This function is called after all the main state changes to
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  // make sure we display the right tab.
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  updateDisplay() {
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    let requestedTabState = this.getTabState(this.requestedTab);
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    let requestedBrowser = this.requestedTab.linkedBrowser;
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    // It is often more desirable to show a blank tab when appropriate than
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    // the tab switch spinner - especially since the spinner is usually
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    // preceded by a perceived lag of TAB_SWITCH_TIMEOUT ms in the
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    // tab switch. We can hide this lag, and hide the time being spent
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						|
    // constructing BrowserChild's, layer trees, etc, by showing a blank
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    // tab instead and focusing it immediately.
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    let shouldBeBlank = false;
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    if (requestedBrowser.isRemoteBrowser) {
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      // If a tab is remote and the window is not minimized, we can show a
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      // blank tab instead of a spinner in the following cases:
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      //
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      // 1. The tab has just crashed, and we haven't started showing the
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      //    tab crashed page yet (in this case, the RemoteTab is null)
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      // 2. The tab has never presented, and has not finished loading
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      //    a non-local-about: page.
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						|
      //
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      // For (2), "finished loading a non-local-about: page" is
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      // determined by the busy state on the tab element and checking
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      // if the loaded URI is local.
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      let isBusy = this.requestedTab.hasAttribute("busy");
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						|
      let isLocalAbout = requestedBrowser.currentURI.schemeIs("about");
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      let hasSufficientlyLoaded = !isBusy && !isLocalAbout;
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      let fl = requestedBrowser.frameLoader;
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      shouldBeBlank =
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        !this.windowHidden &&
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        (!fl.remoteTab ||
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          (!hasSufficientlyLoaded && !fl.remoteTab.hasPresented));
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      if (this.logging()) {
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        let flag = shouldBeBlank ? "blank" : "nonblank";
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        this.addLogFlag(
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          flag,
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          this.windowHidden,
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          fl.remoteTab,
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          isBusy,
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          isLocalAbout,
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          fl.remoteTab ? fl.remoteTab.hasPresented : 0
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        );
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						|
      }
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    }
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						|
 | 
						|
    if (requestedBrowser.isRemoteBrowser) {
 | 
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      this.addLogFlag("isRemote");
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    }
 | 
						|
 | 
						|
    // Figure out which tab we actually want visible right now.
 | 
						|
    let showTab = null;
 | 
						|
    if (
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      requestedTabState != this.STATE_LOADED &&
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      this.lastVisibleTab &&
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      this.loadTimer &&
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						|
      !shouldBeBlank
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    ) {
 | 
						|
      // If we can't show the requestedTab, and lastVisibleTab is
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      // available, show it.
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      showTab = this.lastVisibleTab;
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						|
    } else {
 | 
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      // Show the requested tab. If it's not available, we'll show the spinner or a blank tab.
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      showTab = this.requestedTab;
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    }
 | 
						|
 | 
						|
    // First, let's deal with blank tabs, which we show instead
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						|
    // of the spinner when the tab is not currently set up
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						|
    // properly in the content process.
 | 
						|
    if (!shouldBeBlank && this.blankTab) {
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      this.blankTab.linkedBrowser.removeAttribute("blank");
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      this.blankTab = null;
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						|
    } else if (shouldBeBlank && this.blankTab !== showTab) {
 | 
						|
      if (this.blankTab) {
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        this.blankTab.linkedBrowser.removeAttribute("blank");
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      }
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						|
      this.blankTab = showTab;
 | 
						|
      this.blankTab.linkedBrowser.setAttribute("blank", "true");
 | 
						|
    }
 | 
						|
 | 
						|
    // Show or hide the spinner as needed.
 | 
						|
    let needSpinner =
 | 
						|
      this.getTabState(showTab) != this.STATE_LOADED &&
 | 
						|
      !this.windowHidden &&
 | 
						|
      !shouldBeBlank &&
 | 
						|
      !this.loadTimer;
 | 
						|
 | 
						|
    if (!needSpinner && this.spinnerTab) {
 | 
						|
      this.noteSpinnerHidden();
 | 
						|
      this.tabbrowser.tabpanels.removeAttribute("pendingpaint");
 | 
						|
      this.spinnerTab.linkedBrowser.removeAttribute("pendingpaint");
 | 
						|
      this.spinnerTab = null;
 | 
						|
    } else if (needSpinner && this.spinnerTab !== showTab) {
 | 
						|
      if (this.spinnerTab) {
 | 
						|
        this.spinnerTab.linkedBrowser.removeAttribute("pendingpaint");
 | 
						|
      } else {
 | 
						|
        this.noteSpinnerDisplayed();
 | 
						|
      }
 | 
						|
      this.spinnerTab = showTab;
 | 
						|
      this.tabbrowser.tabpanels.setAttribute("pendingpaint", "true");
 | 
						|
      this.spinnerTab.linkedBrowser.setAttribute("pendingpaint", "true");
 | 
						|
    }
 | 
						|
 | 
						|
    // Switch to the tab we've decided to make visible.
 | 
						|
    if (this.visibleTab !== showTab) {
 | 
						|
      this.tabbrowser._adjustFocusBeforeTabSwitch(this.visibleTab, showTab);
 | 
						|
      this.visibleTab = showTab;
 | 
						|
 | 
						|
      this.maybeVisibleTabs.add(showTab);
 | 
						|
 | 
						|
      let tabpanels = this.tabbrowser.tabpanels;
 | 
						|
      let showPanel = this.tabbrowser.tabContainer.getRelatedElement(showTab);
 | 
						|
      let index = Array.prototype.indexOf.call(tabpanels.children, showPanel);
 | 
						|
      if (index != -1) {
 | 
						|
        this.log(`Switch to tab ${index} - ${this.tinfo(showTab)}`);
 | 
						|
        tabpanels.updateSelectedIndex(index);
 | 
						|
        if (showTab === this.requestedTab) {
 | 
						|
          if (requestedTabState == this.STATE_LOADED) {
 | 
						|
            // The new tab will be made visible in the next paint, record the expected
 | 
						|
            // transaction id for that, and we'll mark when we get notified of its
 | 
						|
            // completion.
 | 
						|
            this.switchPaintId = this.window.windowUtils.lastTransactionId + 1;
 | 
						|
          } else {
 | 
						|
            this.noteMakingTabVisibleWithoutLayers();
 | 
						|
          }
 | 
						|
 | 
						|
          this.tabbrowser._adjustFocusAfterTabSwitch(showTab);
 | 
						|
          this.window.gURLBar.afterTabSwitchFocusChange();
 | 
						|
          this.maybeActivateDocShell(this.requestedTab);
 | 
						|
        }
 | 
						|
      }
 | 
						|
 | 
						|
      // This doesn't necessarily exist if we're a new window and haven't switched tabs yet
 | 
						|
      if (this.lastVisibleTab) {
 | 
						|
        this.lastVisibleTab._visuallySelected = false;
 | 
						|
      }
 | 
						|
 | 
						|
      this.visibleTab._visuallySelected = true;
 | 
						|
      this.tabbrowser.tabContainer._setPositionalAttributes();
 | 
						|
    }
 | 
						|
 | 
						|
    this.lastVisibleTab = this.visibleTab;
 | 
						|
  }
 | 
						|
 | 
						|
  assert(cond) {
 | 
						|
    if (!cond) {
 | 
						|
      dump("Assertion failure\n" + Error().stack);
 | 
						|
 | 
						|
      // Don't break a user's browser if an assertion fails.
 | 
						|
      if (AppConstants.DEBUG) {
 | 
						|
        throw new Error("Assertion failure");
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  maybeClearLoadTimer(caller) {
 | 
						|
    if (this.loadingTab) {
 | 
						|
      this._loadTimerClearedBy = caller;
 | 
						|
      this.loadingTab = null;
 | 
						|
      if (this.loadTimer) {
 | 
						|
        this.clearTimer(this.loadTimer);
 | 
						|
        this.loadTimer = null;
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // We've decided to try to load requestedTab.
 | 
						|
  loadRequestedTab() {
 | 
						|
    this.assert(!this.loadTimer);
 | 
						|
    this.assert(!this.windowHidden);
 | 
						|
 | 
						|
    // loadingTab can be non-null here if we timed out loading the current tab.
 | 
						|
    // In that case we just overwrite it with a different tab; it's had its chance.
 | 
						|
    this.loadingTab = this.requestedTab;
 | 
						|
    this.log("Loading tab " + this.tinfo(this.loadingTab));
 | 
						|
 | 
						|
    this.loadTimer = this.setTimer(
 | 
						|
      () => this.handleEvent({ type: "loadTimeout" }),
 | 
						|
      this.TAB_SWITCH_TIMEOUT
 | 
						|
    );
 | 
						|
    this.setTabState(this.requestedTab, this.STATE_LOADING);
 | 
						|
  }
 | 
						|
 | 
						|
  maybeActivateDocShell(tab) {
 | 
						|
    // If we've reached the point where the requested tab has entered
 | 
						|
    // the loaded state, but the DocShell is still not yet active, we
 | 
						|
    // should activate it.
 | 
						|
    let browser = tab.linkedBrowser;
 | 
						|
    let state = this.getTabState(tab);
 | 
						|
    let canCheckDocShellState =
 | 
						|
      !browser.mDestroyed &&
 | 
						|
      (browser.docShell || browser.frameLoader.remoteTab);
 | 
						|
    if (
 | 
						|
      tab == this.requestedTab &&
 | 
						|
      canCheckDocShellState &&
 | 
						|
      state == this.STATE_LOADED &&
 | 
						|
      !browser.docShellIsActive &&
 | 
						|
      !this.windowHidden
 | 
						|
    ) {
 | 
						|
      browser.docShellIsActive = true;
 | 
						|
      this.logState(
 | 
						|
        "Set requested tab docshell to active and preserveLayers to false"
 | 
						|
      );
 | 
						|
      // If we minimized the window before the switcher was activated,
 | 
						|
      // we might have set the preserveLayers flag for the current
 | 
						|
      // browser. Let's clear it.
 | 
						|
      browser.preserveLayers(false);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // This function runs before every event. It fixes up the state
 | 
						|
  // to account for closed tabs.
 | 
						|
  preActions() {
 | 
						|
    this.assert(this.tabbrowser._switcher);
 | 
						|
    this.assert(this.tabbrowser._switcher === this);
 | 
						|
 | 
						|
    for (let i = 0; i < this.tabLayerCache.length; i++) {
 | 
						|
      let tab = this.tabLayerCache[i];
 | 
						|
      if (!tab.linkedBrowser) {
 | 
						|
        this.tabState.delete(tab);
 | 
						|
        this.tabLayerCache.splice(i, 1);
 | 
						|
        i--;
 | 
						|
      }
 | 
						|
    }
 | 
						|
 | 
						|
    for (let [tab] of this.tabState) {
 | 
						|
      if (!tab.linkedBrowser) {
 | 
						|
        this.tabState.delete(tab);
 | 
						|
        this.unwarmTab(tab);
 | 
						|
      }
 | 
						|
    }
 | 
						|
 | 
						|
    if (this.lastVisibleTab && !this.lastVisibleTab.linkedBrowser) {
 | 
						|
      this.lastVisibleTab = null;
 | 
						|
    }
 | 
						|
    if (this.lastPrimaryTab && !this.lastPrimaryTab.linkedBrowser) {
 | 
						|
      this.lastPrimaryTab = null;
 | 
						|
    }
 | 
						|
    if (this.blankTab && !this.blankTab.linkedBrowser) {
 | 
						|
      this.blankTab = null;
 | 
						|
    }
 | 
						|
    if (this.spinnerTab && !this.spinnerTab.linkedBrowser) {
 | 
						|
      this.noteSpinnerHidden();
 | 
						|
      this.spinnerTab = null;
 | 
						|
    }
 | 
						|
    if (this.loadingTab && !this.loadingTab.linkedBrowser) {
 | 
						|
      this.maybeClearLoadTimer("preActions");
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // This code runs after we've responded to an event or requested a new
 | 
						|
  // tab. It's expected that we've already updated all the principal
 | 
						|
  // state variables. This function takes care of updating any auxilliary
 | 
						|
  // state.
 | 
						|
  postActions(eventString) {
 | 
						|
    // Once we finish loading loadingTab, we null it out. So the state should
 | 
						|
    // always be LOADING.
 | 
						|
    this.assert(
 | 
						|
      !this.loadingTab ||
 | 
						|
        this.getTabState(this.loadingTab) == this.STATE_LOADING
 | 
						|
    );
 | 
						|
 | 
						|
    // We guarantee that loadingTab is non-null iff loadTimer is non-null. So
 | 
						|
    // the timer is set only when we're loading something.
 | 
						|
    this.assert(!this.loadTimer || this.loadingTab);
 | 
						|
    this.assert(!this.loadingTab || this.loadTimer);
 | 
						|
 | 
						|
    // If we're switching to a non-remote tab, there's no need to wait
 | 
						|
    // for it to send layers to the compositor, as this will happen
 | 
						|
    // synchronously. Clearing this here means that in the next step,
 | 
						|
    // we can load the non-remote browser immediately.
 | 
						|
    if (!this.requestedTab.linkedBrowser.isRemoteBrowser) {
 | 
						|
      this.maybeClearLoadTimer("postActions");
 | 
						|
    }
 | 
						|
 | 
						|
    // If we're not loading anything, try loading the requested tab.
 | 
						|
    let stateOfRequestedTab = this.getTabState(this.requestedTab);
 | 
						|
    if (
 | 
						|
      !this.loadTimer &&
 | 
						|
      !this.windowHidden &&
 | 
						|
      (stateOfRequestedTab == this.STATE_UNLOADED ||
 | 
						|
        stateOfRequestedTab == this.STATE_UNLOADING ||
 | 
						|
        this.warmingTabs.has(this.requestedTab))
 | 
						|
    ) {
 | 
						|
      this.assert(stateOfRequestedTab != this.STATE_LOADED);
 | 
						|
      this.loadRequestedTab();
 | 
						|
    }
 | 
						|
 | 
						|
    let numBackgroundCached = 0;
 | 
						|
    for (let tab of this.tabLayerCache) {
 | 
						|
      if (tab !== this.requestedTab) {
 | 
						|
        numBackgroundCached++;
 | 
						|
      }
 | 
						|
    }
 | 
						|
 | 
						|
    // See how many tabs still have work to do.
 | 
						|
    let numPending = 0;
 | 
						|
    let numWarming = 0;
 | 
						|
    for (let [tab, state] of this.tabState) {
 | 
						|
      if (!this.shouldDeactivateDocShell(tab.linkedBrowser)) {
 | 
						|
        continue;
 | 
						|
      }
 | 
						|
 | 
						|
      if (
 | 
						|
        state == this.STATE_LOADED &&
 | 
						|
        tab !== this.requestedTab &&
 | 
						|
        !this.tabLayerCache.includes(tab)
 | 
						|
      ) {
 | 
						|
        numPending++;
 | 
						|
 | 
						|
        if (tab !== this.visibleTab) {
 | 
						|
          numWarming++;
 | 
						|
        }
 | 
						|
      }
 | 
						|
      if (state == this.STATE_LOADING || state == this.STATE_UNLOADING) {
 | 
						|
        numPending++;
 | 
						|
      }
 | 
						|
    }
 | 
						|
 | 
						|
    this.updateDisplay();
 | 
						|
 | 
						|
    // It's possible for updateDisplay to trigger one of our own event
 | 
						|
    // handlers, which might cause finish() to already have been called.
 | 
						|
    // Check for that before calling finish() again.
 | 
						|
    if (!this.tabbrowser._switcher) {
 | 
						|
      return;
 | 
						|
    }
 | 
						|
 | 
						|
    this.maybeFinishTabSwitch();
 | 
						|
 | 
						|
    if (numBackgroundCached > 0) {
 | 
						|
      this.deactivateCachedBackgroundTabs();
 | 
						|
    }
 | 
						|
 | 
						|
    if (numWarming > lazy.gTabWarmingMax) {
 | 
						|
      this.logState("Hit tabWarmingMax");
 | 
						|
      if (this.unloadTimer) {
 | 
						|
        this.clearTimer(this.unloadTimer);
 | 
						|
      }
 | 
						|
      this.unloadNonRequiredTabs();
 | 
						|
    }
 | 
						|
 | 
						|
    if (numPending == 0) {
 | 
						|
      this.finish();
 | 
						|
    }
 | 
						|
 | 
						|
    this.logState("/" + eventString);
 | 
						|
  }
 | 
						|
 | 
						|
  // Fires when we're ready to unload unused tabs.
 | 
						|
  onUnloadTimeout() {
 | 
						|
    this.unloadTimer = null;
 | 
						|
    this.unloadNonRequiredTabs();
 | 
						|
  }
 | 
						|
 | 
						|
  deactivateCachedBackgroundTabs() {
 | 
						|
    for (let tab of this.tabLayerCache) {
 | 
						|
      if (tab !== this.requestedTab) {
 | 
						|
        let browser = tab.linkedBrowser;
 | 
						|
        browser.preserveLayers(true);
 | 
						|
        browser.docShellIsActive = false;
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // If there are any non-visible and non-requested tabs in
 | 
						|
  // STATE_LOADED, sets them to STATE_UNLOADING. Also queues
 | 
						|
  // up the unloadTimer to run onUnloadTimeout if there are still
 | 
						|
  // tabs in the process of unloading.
 | 
						|
  unloadNonRequiredTabs() {
 | 
						|
    this.warmingTabs = new WeakSet();
 | 
						|
    let numPending = 0;
 | 
						|
 | 
						|
    // Unload any tabs that can be unloaded.
 | 
						|
    for (let [tab, state] of this.tabState) {
 | 
						|
      if (!this.shouldDeactivateDocShell(tab.linkedBrowser)) {
 | 
						|
        continue;
 | 
						|
      }
 | 
						|
 | 
						|
      let isInLayerCache = this.tabLayerCache.includes(tab);
 | 
						|
 | 
						|
      if (
 | 
						|
        state == this.STATE_LOADED &&
 | 
						|
        !this.maybeVisibleTabs.has(tab) &&
 | 
						|
        tab !== this.lastVisibleTab &&
 | 
						|
        tab !== this.loadingTab &&
 | 
						|
        tab !== this.requestedTab &&
 | 
						|
        !isInLayerCache
 | 
						|
      ) {
 | 
						|
        this.setTabState(tab, this.STATE_UNLOADING);
 | 
						|
      }
 | 
						|
 | 
						|
      if (
 | 
						|
        state != this.STATE_UNLOADED &&
 | 
						|
        tab !== this.requestedTab &&
 | 
						|
        !isInLayerCache
 | 
						|
      ) {
 | 
						|
        numPending++;
 | 
						|
      }
 | 
						|
    }
 | 
						|
 | 
						|
    if (numPending) {
 | 
						|
      // Keep the timer going since there may be more tabs to unload.
 | 
						|
      this.unloadTimer = this.setTimer(
 | 
						|
        () => this.handleEvent({ type: "unloadTimeout" }),
 | 
						|
        this.UNLOAD_DELAY
 | 
						|
      );
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // Fires when an ongoing load has taken too long.
 | 
						|
  onLoadTimeout() {
 | 
						|
    this.maybeClearLoadTimer("onLoadTimeout");
 | 
						|
  }
 | 
						|
 | 
						|
  // Fires when the layers become available for a tab.
 | 
						|
  onLayersReady(browser) {
 | 
						|
    let tab = this.tabbrowser.getTabForBrowser(browser);
 | 
						|
    if (!tab) {
 | 
						|
      // We probably got a layer update from a tab that got before
 | 
						|
      // the switcher was created, or for browser that's not being
 | 
						|
      // tracked by the async tab switcher (like the preloaded about:newtab).
 | 
						|
      return;
 | 
						|
    }
 | 
						|
 | 
						|
    this.logState(`onLayersReady(${tab._tPos}, ${browser.isRemoteBrowser})`);
 | 
						|
 | 
						|
    this.assert(
 | 
						|
      this.getTabState(tab) == this.STATE_LOADING ||
 | 
						|
        this.getTabState(tab) == this.STATE_LOADED
 | 
						|
    );
 | 
						|
    this.setTabState(tab, this.STATE_LOADED);
 | 
						|
    this.unwarmTab(tab);
 | 
						|
 | 
						|
    if (this.loadingTab === tab) {
 | 
						|
      this.maybeClearLoadTimer("onLayersReady");
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // Fires when we paint the screen. Any tab switches we initiated
 | 
						|
  // previously are done, so there's no need to keep the old layers
 | 
						|
  // around.
 | 
						|
  onPaint(event) {
 | 
						|
    this.addLogFlag(
 | 
						|
      "onPaint",
 | 
						|
      this.switchPaintId != -1,
 | 
						|
      event.transactionId >= this.switchPaintId
 | 
						|
    );
 | 
						|
    this.notePaint(event);
 | 
						|
    this.maybeVisibleTabs.clear();
 | 
						|
  }
 | 
						|
 | 
						|
  // Called when we're done clearing the layers for a tab.
 | 
						|
  onLayersCleared(browser) {
 | 
						|
    let tab = this.tabbrowser.getTabForBrowser(browser);
 | 
						|
    if (tab) {
 | 
						|
      this.logState(`onLayersCleared(${tab._tPos})`);
 | 
						|
      this.assert(
 | 
						|
        this.getTabState(tab) == this.STATE_UNLOADING ||
 | 
						|
          this.getTabState(tab) == this.STATE_UNLOADED
 | 
						|
      );
 | 
						|
      this.setTabState(tab, this.STATE_UNLOADED);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // Called when a tab switches from remote to non-remote. In this case
 | 
						|
  // a MozLayerTreeReady notification that we requested may never fire,
 | 
						|
  // so we need to simulate it.
 | 
						|
  onRemotenessChange(tab) {
 | 
						|
    this.logState(
 | 
						|
      `onRemotenessChange(${tab._tPos}, ${tab.linkedBrowser.isRemoteBrowser})`
 | 
						|
    );
 | 
						|
    if (!tab.linkedBrowser.isRemoteBrowser) {
 | 
						|
      if (this.getTabState(tab) == this.STATE_LOADING) {
 | 
						|
        this.onLayersReady(tab.linkedBrowser);
 | 
						|
      } else if (this.getTabState(tab) == this.STATE_UNLOADING) {
 | 
						|
        this.onLayersCleared(tab.linkedBrowser);
 | 
						|
      }
 | 
						|
    } else if (this.getTabState(tab) == this.STATE_LOADED) {
 | 
						|
      // A tab just changed from non-remote to remote, which means
 | 
						|
      // that it's gone back into the STATE_LOADING state until
 | 
						|
      // it sends up a layer tree.
 | 
						|
      this.setTabState(tab, this.STATE_LOADING);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  onTabRemoved(tab) {
 | 
						|
    if (this.lastVisibleTab == tab) {
 | 
						|
      this.handleEvent({ type: "tabRemoved", tab });
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // Called when a tab has been removed, and the browser node is
 | 
						|
  // about to be removed from the DOM.
 | 
						|
  onTabRemovedImpl(tab) {
 | 
						|
    this.lastVisibleTab = null;
 | 
						|
  }
 | 
						|
 | 
						|
  onVisibilityChange() {
 | 
						|
    if (this.windowHidden) {
 | 
						|
      for (let [tab, state] of this.tabState) {
 | 
						|
        if (!this.shouldDeactivateDocShell(tab.linkedBrowser)) {
 | 
						|
          continue;
 | 
						|
        }
 | 
						|
 | 
						|
        if (state == this.STATE_LOADING || state == this.STATE_LOADED) {
 | 
						|
          this.setTabState(tab, this.STATE_UNLOADING);
 | 
						|
        }
 | 
						|
      }
 | 
						|
      this.maybeClearLoadTimer("onSizeModeOrOcc");
 | 
						|
    } else {
 | 
						|
      // We're no longer minimized or occluded. This means we might want
 | 
						|
      // to activate the current tab's docShell.
 | 
						|
      this.maybeActivateDocShell(this.tabbrowser.selectedTab);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  onSwapDocShells(ourBrowser, otherBrowser) {
 | 
						|
    // This event fires before the swap. ourBrowser is from
 | 
						|
    // our window. We save the state of otherBrowser since ourBrowser
 | 
						|
    // needs to take on that state at the end of the swap.
 | 
						|
 | 
						|
    let otherTabbrowser = otherBrowser.ownerGlobal.gBrowser;
 | 
						|
    let otherState;
 | 
						|
    if (otherTabbrowser && otherTabbrowser._switcher) {
 | 
						|
      let otherTab = otherTabbrowser.getTabForBrowser(otherBrowser);
 | 
						|
      let otherSwitcher = otherTabbrowser._switcher;
 | 
						|
      otherState = otherSwitcher.getTabState(otherTab);
 | 
						|
    } else {
 | 
						|
      otherState = otherBrowser.docShellIsActive
 | 
						|
        ? this.STATE_LOADED
 | 
						|
        : this.STATE_UNLOADED;
 | 
						|
    }
 | 
						|
    if (!this.swapMap) {
 | 
						|
      this.swapMap = new WeakMap();
 | 
						|
    }
 | 
						|
    this.swapMap.set(otherBrowser, {
 | 
						|
      state: otherState,
 | 
						|
    });
 | 
						|
  }
 | 
						|
 | 
						|
  onEndSwapDocShells(ourBrowser, otherBrowser) {
 | 
						|
    // The swap has happened. We reset the loadingTab in
 | 
						|
    // case it has been swapped. We also set ourBrowser's state
 | 
						|
    // to whatever otherBrowser's state was before the swap.
 | 
						|
 | 
						|
    // Clearing the load timer means that we will
 | 
						|
    // immediately display a spinner if ourBrowser isn't
 | 
						|
    // ready yet. Typically it will already be ready
 | 
						|
    // though. If it's not, we're probably in a new window,
 | 
						|
    // in which case we have no other tabs to display anyway.
 | 
						|
    this.maybeClearLoadTimer("onEndSwapDocShells");
 | 
						|
 | 
						|
    let { state: otherState } = this.swapMap.get(otherBrowser);
 | 
						|
 | 
						|
    this.swapMap.delete(otherBrowser);
 | 
						|
 | 
						|
    let ourTab = this.tabbrowser.getTabForBrowser(ourBrowser);
 | 
						|
    if (ourTab) {
 | 
						|
      this.setTabStateNoAction(ourTab, otherState);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  /**
 | 
						|
   * Check if the browser should be deactivated. If the browser is a print preivew or
 | 
						|
   * PiP browser then we won't deactive it.
 | 
						|
   * @param browser The browser to check if it should be deactivated
 | 
						|
   * @returns false if a print preview or PiP browser else true
 | 
						|
   */
 | 
						|
  shouldDeactivateDocShell(browser) {
 | 
						|
    return !(
 | 
						|
      this.tabbrowser._printPreviewBrowsers.has(browser) ||
 | 
						|
      lazy.PictureInPicture.isOriginatingBrowser(browser)
 | 
						|
    );
 | 
						|
  }
 | 
						|
 | 
						|
  shouldActivateDocShell(browser) {
 | 
						|
    let tab = this.tabbrowser.getTabForBrowser(browser);
 | 
						|
    let state = this.getTabState(tab);
 | 
						|
    return state == this.STATE_LOADING || state == this.STATE_LOADED;
 | 
						|
  }
 | 
						|
 | 
						|
  activateBrowserForPrintPreview(browser) {
 | 
						|
    let tab = this.tabbrowser.getTabForBrowser(browser);
 | 
						|
    let state = this.getTabState(tab);
 | 
						|
    if (state != this.STATE_LOADING && state != this.STATE_LOADED) {
 | 
						|
      this.setTabState(tab, this.STATE_LOADING);
 | 
						|
      this.logState(
 | 
						|
        "Activated browser " + this.tinfo(tab) + " for print preview"
 | 
						|
      );
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  canWarmTab(tab) {
 | 
						|
    if (!lazy.gTabWarmingEnabled) {
 | 
						|
      return false;
 | 
						|
    }
 | 
						|
 | 
						|
    if (!tab) {
 | 
						|
      return false;
 | 
						|
    }
 | 
						|
 | 
						|
    // If the tab is not yet inserted, closing, not remote,
 | 
						|
    // crashed, already visible, or already requested, warming
 | 
						|
    // up the tab makes no sense.
 | 
						|
    if (
 | 
						|
      this.windowHidden ||
 | 
						|
      !tab.linkedPanel ||
 | 
						|
      tab.closing ||
 | 
						|
      !tab.linkedBrowser.isRemoteBrowser ||
 | 
						|
      !tab.linkedBrowser.frameLoader.remoteTab
 | 
						|
    ) {
 | 
						|
      return false;
 | 
						|
    }
 | 
						|
 | 
						|
    return true;
 | 
						|
  }
 | 
						|
 | 
						|
  shouldWarmTab(tab) {
 | 
						|
    if (this.canWarmTab(tab)) {
 | 
						|
      // Tabs that are already in STATE_LOADING or STATE_LOADED
 | 
						|
      // have no need to be warmed up.
 | 
						|
      let state = this.getTabState(tab);
 | 
						|
      if (state === this.STATE_UNLOADING || state === this.STATE_UNLOADED) {
 | 
						|
        return true;
 | 
						|
      }
 | 
						|
    }
 | 
						|
 | 
						|
    return false;
 | 
						|
  }
 | 
						|
 | 
						|
  unwarmTab(tab) {
 | 
						|
    this.warmingTabs.delete(tab);
 | 
						|
  }
 | 
						|
 | 
						|
  warmupTab(tab) {
 | 
						|
    if (!this.shouldWarmTab(tab)) {
 | 
						|
      return;
 | 
						|
    }
 | 
						|
 | 
						|
    this.logState("warmupTab " + this.tinfo(tab));
 | 
						|
 | 
						|
    this.warmingTabs.add(tab);
 | 
						|
    this.setTabState(tab, this.STATE_LOADING);
 | 
						|
    this.queueUnload(lazy.gTabWarmingUnloadDelayMs);
 | 
						|
  }
 | 
						|
 | 
						|
  cleanUpTabAfterEviction(tab) {
 | 
						|
    this.assert(tab !== this.requestedTab);
 | 
						|
    let browser = tab.linkedBrowser;
 | 
						|
    if (browser) {
 | 
						|
      browser.preserveLayers(false);
 | 
						|
    }
 | 
						|
    this.setTabState(tab, this.STATE_UNLOADING);
 | 
						|
  }
 | 
						|
 | 
						|
  evictOldestTabFromCache() {
 | 
						|
    let tab = this.tabLayerCache.shift();
 | 
						|
    this.cleanUpTabAfterEviction(tab);
 | 
						|
  }
 | 
						|
 | 
						|
  maybePromoteTabInLayerCache(tab) {
 | 
						|
    if (
 | 
						|
      lazy.gTabCacheSize > 1 &&
 | 
						|
      tab.linkedBrowser.isRemoteBrowser &&
 | 
						|
      tab.linkedBrowser.currentURI.spec != "about:blank"
 | 
						|
    ) {
 | 
						|
      let tabIndex = this.tabLayerCache.indexOf(tab);
 | 
						|
 | 
						|
      if (tabIndex != -1) {
 | 
						|
        this.tabLayerCache.splice(tabIndex, 1);
 | 
						|
      }
 | 
						|
 | 
						|
      this.tabLayerCache.push(tab);
 | 
						|
 | 
						|
      if (this.tabLayerCache.length > lazy.gTabCacheSize) {
 | 
						|
        this.evictOldestTabFromCache();
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // Called when the user asks to switch to a given tab.
 | 
						|
  requestTab(tab) {
 | 
						|
    if (tab === this.requestedTab) {
 | 
						|
      return;
 | 
						|
    }
 | 
						|
 | 
						|
    let tabState = this.getTabState(tab);
 | 
						|
    this.noteTabRequested(tab, tabState);
 | 
						|
 | 
						|
    this.logState("requestTab " + this.tinfo(tab));
 | 
						|
    this.startTabSwitch();
 | 
						|
 | 
						|
    let oldBrowser = this.requestedTab.linkedBrowser;
 | 
						|
    oldBrowser.deprioritize();
 | 
						|
    this.requestedTab = tab;
 | 
						|
    if (tabState == this.STATE_LOADED) {
 | 
						|
      this.maybeVisibleTabs.clear();
 | 
						|
    }
 | 
						|
 | 
						|
    tab.linkedBrowser.setAttribute("primary", "true");
 | 
						|
    if (this.lastPrimaryTab && this.lastPrimaryTab != tab) {
 | 
						|
      this.lastPrimaryTab.linkedBrowser.removeAttribute("primary");
 | 
						|
    }
 | 
						|
    this.lastPrimaryTab = tab;
 | 
						|
 | 
						|
    this.queueUnload(this.UNLOAD_DELAY);
 | 
						|
  }
 | 
						|
 | 
						|
  queueUnload(unloadTimeout) {
 | 
						|
    this.handleEvent({ type: "queueUnload", unloadTimeout });
 | 
						|
  }
 | 
						|
 | 
						|
  onQueueUnload(unloadTimeout) {
 | 
						|
    if (this.unloadTimer) {
 | 
						|
      this.clearTimer(this.unloadTimer);
 | 
						|
    }
 | 
						|
    this.unloadTimer = this.setTimer(
 | 
						|
      () => this.handleEvent({ type: "unloadTimeout" }),
 | 
						|
      unloadTimeout
 | 
						|
    );
 | 
						|
  }
 | 
						|
 | 
						|
  handleEvent(event, delayed = false) {
 | 
						|
    if (this._processing) {
 | 
						|
      this.setTimer(() => this.handleEvent(event, true), 0);
 | 
						|
      return;
 | 
						|
    }
 | 
						|
    if (delayed && this.tabbrowser._switcher != this) {
 | 
						|
      // if we delayed processing this event, we might be out of date, in which
 | 
						|
      // case we drop the delayed events
 | 
						|
      return;
 | 
						|
    }
 | 
						|
    this._processing = true;
 | 
						|
    try {
 | 
						|
      this.preActions();
 | 
						|
 | 
						|
      switch (event.type) {
 | 
						|
        case "queueUnload":
 | 
						|
          this.onQueueUnload(event.unloadTimeout);
 | 
						|
          break;
 | 
						|
        case "unloadTimeout":
 | 
						|
          this.onUnloadTimeout();
 | 
						|
          break;
 | 
						|
        case "loadTimeout":
 | 
						|
          this.onLoadTimeout();
 | 
						|
          break;
 | 
						|
        case "tabRemoved":
 | 
						|
          this.onTabRemovedImpl(event.tab);
 | 
						|
          break;
 | 
						|
        case "MozLayerTreeReady":
 | 
						|
          this.onLayersReady(event.originalTarget);
 | 
						|
          break;
 | 
						|
        case "MozAfterPaint":
 | 
						|
          this.onPaint(event);
 | 
						|
          break;
 | 
						|
        case "MozLayerTreeCleared":
 | 
						|
          this.onLayersCleared(event.originalTarget);
 | 
						|
          break;
 | 
						|
        case "TabRemotenessChange":
 | 
						|
          this.onRemotenessChange(event.target);
 | 
						|
          break;
 | 
						|
        case "visibilitychange":
 | 
						|
          this.onVisibilityChange();
 | 
						|
          break;
 | 
						|
        case "SwapDocShells":
 | 
						|
          this.onSwapDocShells(event.originalTarget, event.detail);
 | 
						|
          break;
 | 
						|
        case "EndSwapDocShells":
 | 
						|
          this.onEndSwapDocShells(event.originalTarget, event.detail);
 | 
						|
          break;
 | 
						|
      }
 | 
						|
 | 
						|
      this.postActions(event.type);
 | 
						|
    } finally {
 | 
						|
      this._processing = false;
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  /*
 | 
						|
   * Telemetry and Profiler related helpers for recording tab switch
 | 
						|
   * timing.
 | 
						|
   */
 | 
						|
 | 
						|
  startTabSwitch() {
 | 
						|
    this.noteStartTabSwitch();
 | 
						|
    this.switchInProgress = true;
 | 
						|
  }
 | 
						|
 | 
						|
  /**
 | 
						|
   * Something has occurred that might mean that we've completed
 | 
						|
   * the tab switch (layers are ready, paints are done, spinners
 | 
						|
   * are hidden). This checks to make sure all conditions are
 | 
						|
   * satisfied, and then records the tab switch as finished.
 | 
						|
   */
 | 
						|
  maybeFinishTabSwitch() {
 | 
						|
    if (
 | 
						|
      this.switchInProgress &&
 | 
						|
      this.requestedTab &&
 | 
						|
      (this.getTabState(this.requestedTab) == this.STATE_LOADED ||
 | 
						|
        this.requestedTab === this.blankTab)
 | 
						|
    ) {
 | 
						|
      if (this.requestedTab !== this.blankTab) {
 | 
						|
        this.maybePromoteTabInLayerCache(this.requestedTab);
 | 
						|
      }
 | 
						|
 | 
						|
      this.noteFinishTabSwitch();
 | 
						|
      this.switchInProgress = false;
 | 
						|
 | 
						|
      let event = new this.window.CustomEvent("TabSwitched", {
 | 
						|
        bubbles: true,
 | 
						|
        detail: {
 | 
						|
          tab: this.requestedTab,
 | 
						|
        },
 | 
						|
      });
 | 
						|
      this.tabbrowser.dispatchEvent(event);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  /*
 | 
						|
   * Debug related logging for switcher.
 | 
						|
   */
 | 
						|
  logging() {
 | 
						|
    if (this._useDumpForLogging) {
 | 
						|
      return true;
 | 
						|
    }
 | 
						|
    if (this._logInit) {
 | 
						|
      return this._shouldLog;
 | 
						|
    }
 | 
						|
    let result = Services.prefs.getBoolPref(
 | 
						|
      "browser.tabs.remote.logSwitchTiming",
 | 
						|
      false
 | 
						|
    );
 | 
						|
    this._shouldLog = result;
 | 
						|
    this._logInit = true;
 | 
						|
    return this._shouldLog;
 | 
						|
  }
 | 
						|
 | 
						|
  tinfo(tab) {
 | 
						|
    if (tab) {
 | 
						|
      return tab._tPos + "(" + tab.linkedBrowser.currentURI.spec + ")";
 | 
						|
    }
 | 
						|
    return "null";
 | 
						|
  }
 | 
						|
 | 
						|
  log(s) {
 | 
						|
    if (!this.logging()) {
 | 
						|
      return;
 | 
						|
    }
 | 
						|
    if (this._useDumpForLogging) {
 | 
						|
      dump(s + "\n");
 | 
						|
    } else {
 | 
						|
      Services.console.logStringMessage(s);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  addLogFlag(flag, ...subFlags) {
 | 
						|
    if (this.logging()) {
 | 
						|
      if (subFlags.length) {
 | 
						|
        flag += `(${subFlags.map(f => (f ? 1 : 0)).join("")})`;
 | 
						|
      }
 | 
						|
      this._logFlags.push(flag);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  logState(suffix) {
 | 
						|
    if (!this.logging()) {
 | 
						|
      return;
 | 
						|
    }
 | 
						|
 | 
						|
    let getTabString = tab => {
 | 
						|
      let tabString = "";
 | 
						|
 | 
						|
      let state = this.getTabState(tab);
 | 
						|
      let isWarming = this.warmingTabs.has(tab);
 | 
						|
      let isCached = this.tabLayerCache.includes(tab);
 | 
						|
      let isClosing = tab.closing;
 | 
						|
      let linkedBrowser = tab.linkedBrowser;
 | 
						|
      let isActive = linkedBrowser && linkedBrowser.docShellIsActive;
 | 
						|
      let isRendered = linkedBrowser && linkedBrowser.renderLayers;
 | 
						|
      let isPiP =
 | 
						|
        linkedBrowser &&
 | 
						|
        lazy.PictureInPicture.isOriginatingBrowser(linkedBrowser);
 | 
						|
 | 
						|
      if (tab === this.lastVisibleTab) {
 | 
						|
        tabString += "V";
 | 
						|
      }
 | 
						|
      if (tab === this.loadingTab) {
 | 
						|
        tabString += "L";
 | 
						|
      }
 | 
						|
      if (tab === this.requestedTab) {
 | 
						|
        tabString += "R";
 | 
						|
      }
 | 
						|
      if (tab === this.blankTab) {
 | 
						|
        tabString += "B";
 | 
						|
      }
 | 
						|
      if (this.maybeVisibleTabs.has(tab)) {
 | 
						|
        tabString += "M";
 | 
						|
      }
 | 
						|
 | 
						|
      let extraStates = "";
 | 
						|
      if (isWarming) {
 | 
						|
        extraStates += "W";
 | 
						|
      }
 | 
						|
      if (isCached) {
 | 
						|
        extraStates += "C";
 | 
						|
      }
 | 
						|
      if (isClosing) {
 | 
						|
        extraStates += "X";
 | 
						|
      }
 | 
						|
      if (isActive) {
 | 
						|
        extraStates += "A";
 | 
						|
      }
 | 
						|
      if (isRendered) {
 | 
						|
        extraStates += "R";
 | 
						|
      }
 | 
						|
      if (isPiP) {
 | 
						|
        extraStates += "P";
 | 
						|
      }
 | 
						|
      if (extraStates != "") {
 | 
						|
        tabString += `(${extraStates})`;
 | 
						|
      }
 | 
						|
 | 
						|
      switch (state) {
 | 
						|
        case this.STATE_LOADED: {
 | 
						|
          tabString += "(loaded)";
 | 
						|
          break;
 | 
						|
        }
 | 
						|
        case this.STATE_LOADING: {
 | 
						|
          tabString += "(loading)";
 | 
						|
          break;
 | 
						|
        }
 | 
						|
        case this.STATE_UNLOADING: {
 | 
						|
          tabString += "(unloading)";
 | 
						|
          break;
 | 
						|
        }
 | 
						|
        case this.STATE_UNLOADED: {
 | 
						|
          tabString += "(unloaded)";
 | 
						|
          break;
 | 
						|
        }
 | 
						|
      }
 | 
						|
 | 
						|
      return tabString;
 | 
						|
    };
 | 
						|
 | 
						|
    let accum = "";
 | 
						|
 | 
						|
    // This is a bit tricky to read, but what we're doing here is collapsing
 | 
						|
    // identical tab states down to make the overal string shorter and easier
 | 
						|
    // to read, and we move all simply unloaded tabs to the back of the list.
 | 
						|
    // I.e., we turn
 | 
						|
    //   "0:(unloaded) 1:(unloaded) 2:(unloaded) 3:(loaded)""
 | 
						|
    // into
 | 
						|
    //   "3:(loaded) 0...2:(unloaded)"
 | 
						|
    let tabStrings = this.tabbrowser.tabs.map(t => getTabString(t));
 | 
						|
    let lastMatch = -1;
 | 
						|
    let unloadedTabsStrings = [];
 | 
						|
    for (let i = 0; i <= tabStrings.length; i++) {
 | 
						|
      if (i > 0) {
 | 
						|
        if (i < tabStrings.length && tabStrings[i] == tabStrings[lastMatch]) {
 | 
						|
          continue;
 | 
						|
        }
 | 
						|
 | 
						|
        if (tabStrings[lastMatch] == "(unloaded)") {
 | 
						|
          if (lastMatch == i - 1) {
 | 
						|
            unloadedTabsStrings.push(lastMatch.toString());
 | 
						|
          } else {
 | 
						|
            unloadedTabsStrings.push(`${lastMatch}...${i - 1}`);
 | 
						|
          }
 | 
						|
        } else if (lastMatch == i - 1) {
 | 
						|
          accum += `${lastMatch}:${tabStrings[lastMatch]} `;
 | 
						|
        } else {
 | 
						|
          accum += `${lastMatch}...${i - 1}:${tabStrings[lastMatch]} `;
 | 
						|
        }
 | 
						|
      }
 | 
						|
 | 
						|
      lastMatch = i;
 | 
						|
    }
 | 
						|
 | 
						|
    if (unloadedTabsStrings.length) {
 | 
						|
      accum += `${unloadedTabsStrings.join(",")}:(unloaded) `;
 | 
						|
    }
 | 
						|
 | 
						|
    accum += "cached: " + this.tabLayerCache.length + " ";
 | 
						|
 | 
						|
    if (this._logFlags.length) {
 | 
						|
      accum += `[${this._logFlags.join(",")}] `;
 | 
						|
      this._logFlags = [];
 | 
						|
    }
 | 
						|
 | 
						|
    // It can be annoying to read through the entirety of a log string just
 | 
						|
    // to check if something changed or not. So if we can tell that nothing
 | 
						|
    // changed, just write "unchanged" to save the reader's time.
 | 
						|
    let logString;
 | 
						|
    if (this._lastLogString == accum) {
 | 
						|
      accum = "unchanged";
 | 
						|
    } else {
 | 
						|
      this._lastLogString = accum;
 | 
						|
    }
 | 
						|
    logString = `ATS: ${accum}{${suffix}}`;
 | 
						|
 | 
						|
    if (this._useDumpForLogging) {
 | 
						|
      dump(logString + "\n");
 | 
						|
    } else {
 | 
						|
      Services.console.logStringMessage(logString);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  noteMakingTabVisibleWithoutLayers() {
 | 
						|
    // We're making the tab visible even though we haven't yet got layers for it.
 | 
						|
    // It's hard to know which composite the layers will first be available in (and
 | 
						|
    // the parent process might not even get MozAfterPaint delivered for it), so just
 | 
						|
    // give up measuring this for now. :(
 | 
						|
    TelemetryStopwatch.cancel("FX_TAB_SWITCH_COMPOSITE_E10S_MS", this.window);
 | 
						|
  }
 | 
						|
 | 
						|
  notePaint(event) {
 | 
						|
    if (this.switchPaintId != -1 && event.transactionId >= this.switchPaintId) {
 | 
						|
      if (
 | 
						|
        TelemetryStopwatch.running(
 | 
						|
          "FX_TAB_SWITCH_COMPOSITE_E10S_MS",
 | 
						|
          this.window
 | 
						|
        )
 | 
						|
      ) {
 | 
						|
        let time = TelemetryStopwatch.timeElapsed(
 | 
						|
          "FX_TAB_SWITCH_COMPOSITE_E10S_MS",
 | 
						|
          this.window
 | 
						|
        );
 | 
						|
        if (time != -1) {
 | 
						|
          TelemetryStopwatch.finish(
 | 
						|
            "FX_TAB_SWITCH_COMPOSITE_E10S_MS",
 | 
						|
            this.window
 | 
						|
          );
 | 
						|
        }
 | 
						|
      }
 | 
						|
      let { innerWindowId } = this.window.windowGlobalChild;
 | 
						|
      ChromeUtils.addProfilerMarker("AsyncTabSwitch:Composited", {
 | 
						|
        innerWindowId,
 | 
						|
      });
 | 
						|
      this.switchPaintId = -1;
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  noteTabRequested(tab, tabState) {
 | 
						|
    if (lazy.gTabWarmingEnabled) {
 | 
						|
      let warmingState = "disqualified";
 | 
						|
 | 
						|
      if (this.canWarmTab(tab)) {
 | 
						|
        if (tabState == this.STATE_LOADING) {
 | 
						|
          warmingState = "stillLoading";
 | 
						|
        } else if (tabState == this.STATE_LOADED) {
 | 
						|
          warmingState = "loaded";
 | 
						|
        } else if (
 | 
						|
          tabState == this.STATE_UNLOADING ||
 | 
						|
          tabState == this.STATE_UNLOADED
 | 
						|
        ) {
 | 
						|
          // At this point, if the tab's browser was being inserted
 | 
						|
          // lazily, we never had a chance to warm it up, and unfortunately
 | 
						|
          // there's no great way to detect that case. Those cases will
 | 
						|
          // end up in the "notWarmed" bucket, along with legitimate cases
 | 
						|
          // where tabs could have been warmed but weren't.
 | 
						|
          warmingState = "notWarmed";
 | 
						|
        }
 | 
						|
      }
 | 
						|
 | 
						|
      Services.telemetry
 | 
						|
        .getHistogramById("FX_TAB_SWITCH_REQUEST_TAB_WARMING_STATE")
 | 
						|
        .add(warmingState);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  noteStartTabSwitch() {
 | 
						|
    TelemetryStopwatch.cancel("FX_TAB_SWITCH_TOTAL_E10S_MS", this.window);
 | 
						|
    TelemetryStopwatch.start("FX_TAB_SWITCH_TOTAL_E10S_MS", this.window);
 | 
						|
 | 
						|
    if (
 | 
						|
      TelemetryStopwatch.running("FX_TAB_SWITCH_COMPOSITE_E10S_MS", this.window)
 | 
						|
    ) {
 | 
						|
      TelemetryStopwatch.cancel("FX_TAB_SWITCH_COMPOSITE_E10S_MS", this.window);
 | 
						|
    }
 | 
						|
    TelemetryStopwatch.start("FX_TAB_SWITCH_COMPOSITE_E10S_MS", this.window);
 | 
						|
    let { innerWindowId } = this.window.windowGlobalChild;
 | 
						|
    ChromeUtils.addProfilerMarker("AsyncTabSwitch:Start", { innerWindowId });
 | 
						|
  }
 | 
						|
 | 
						|
  noteFinishTabSwitch() {
 | 
						|
    // After this point the tab has switched from the content thread's point of view.
 | 
						|
    // The changes will be visible after the next refresh driver tick + composite.
 | 
						|
    let time = TelemetryStopwatch.timeElapsed(
 | 
						|
      "FX_TAB_SWITCH_TOTAL_E10S_MS",
 | 
						|
      this.window
 | 
						|
    );
 | 
						|
    if (time != -1) {
 | 
						|
      TelemetryStopwatch.finish("FX_TAB_SWITCH_TOTAL_E10S_MS", this.window);
 | 
						|
      this.log("DEBUG: tab switch time = " + time);
 | 
						|
      let { innerWindowId } = this.window.windowGlobalChild;
 | 
						|
      ChromeUtils.addProfilerMarker("AsyncTabSwitch:Finish", { innerWindowId });
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  noteSpinnerDisplayed() {
 | 
						|
    this.assert(!this.spinnerTab);
 | 
						|
    let browser = this.requestedTab.linkedBrowser;
 | 
						|
    this.assert(browser.isRemoteBrowser);
 | 
						|
    TelemetryStopwatch.start("FX_TAB_SWITCH_SPINNER_VISIBLE_MS", this.window);
 | 
						|
    // We have a second, similar probe for capturing recordings of
 | 
						|
    // when the spinner is displayed for very long periods.
 | 
						|
    TelemetryStopwatch.start(
 | 
						|
      "FX_TAB_SWITCH_SPINNER_VISIBLE_LONG_MS",
 | 
						|
      this.window
 | 
						|
    );
 | 
						|
    let { innerWindowId } = this.window.windowGlobalChild;
 | 
						|
    ChromeUtils.addProfilerMarker("AsyncTabSwitch:SpinnerShown", {
 | 
						|
      innerWindowId,
 | 
						|
    });
 | 
						|
    Services.telemetry
 | 
						|
      .getHistogramById("FX_TAB_SWITCH_SPINNER_VISIBLE_TRIGGER")
 | 
						|
      .add(this._loadTimerClearedBy);
 | 
						|
    if (AppConstants.NIGHTLY_BUILD) {
 | 
						|
      Services.obs.notifyObservers(null, "tabswitch-spinner");
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  noteSpinnerHidden() {
 | 
						|
    this.assert(this.spinnerTab);
 | 
						|
    this.log(
 | 
						|
      "DEBUG: spinner time = " +
 | 
						|
        TelemetryStopwatch.timeElapsed(
 | 
						|
          "FX_TAB_SWITCH_SPINNER_VISIBLE_MS",
 | 
						|
          this.window
 | 
						|
        )
 | 
						|
    );
 | 
						|
    TelemetryStopwatch.finish("FX_TAB_SWITCH_SPINNER_VISIBLE_MS", this.window);
 | 
						|
    TelemetryStopwatch.finish(
 | 
						|
      "FX_TAB_SWITCH_SPINNER_VISIBLE_LONG_MS",
 | 
						|
      this.window
 | 
						|
    );
 | 
						|
    let { innerWindowId } = this.window.windowGlobalChild;
 | 
						|
    ChromeUtils.addProfilerMarker("AsyncTabSwitch:SpinnerHidden", {
 | 
						|
      innerWindowId,
 | 
						|
    });
 | 
						|
    // we do not get a onPaint after displaying the spinner
 | 
						|
    this._loadTimerClearedBy = "none";
 | 
						|
  }
 | 
						|
}
 |