Bug 1358815 - remove sync reflow from find bar initialization, r=jaws

This removes the sync reflow from almost all cases. The only case where we keep it is when a keypress
caught in content triggers a sync message to the parent process. We should clean this up in bug 1371523.

I've tried to fix the tests, but a lot of them seem to be disabled anyway...

MozReview-Commit-ID: 9k36p7q8MKy

--HG--
extra : rebase_source : 311ee41ba9456a5c5d58b81a0cfa999bcef0027e

browser/base/content/browser-sets.inc

@@ -44,16 +44,16 @@
     <command id="View:FullScreen" oncommand="BrowserFullScreen();"/>
     <command id="View:ReaderView" oncommand="ReaderParent.toggleReaderMode(event);"/>
     <command id="cmd_find"
-             oncommand="gFindBar.onFindCommand();"
+             oncommand="gLazyFindCommand('onFindCommand')"
              observes="isImage"/>
     <command id="cmd_findAgain"
-             oncommand="gFindBar.onFindAgainCommand(false);"
+             oncommand="gLazyFindCommand('onFindAgainCommand', false)"
              observes="isImage"/>
     <command id="cmd_findPrevious"
-             oncommand="gFindBar.onFindAgainCommand(true);"
+             oncommand="gLazyFindCommand('onFindAgainCommand', true)"
              observes="isImage"/>
 #ifdef XP_MACOSX
-    <command id="cmd_findSelection" oncommand="gFindBar.onFindSelectionCommand();"/>
+    <command id="cmd_findSelection" oncommand="gLazyFindCommand('onFindSelectionCommand')"/>
 #endif
     <!-- work-around bug 392512 -->
     <command id="Browser:AddBookmarkAs"

browser/base/content/browser.js

@@ -266,7 +266,7 @@ Object.defineProperty(this, "gFindBar", {
   configurable: true,
   enumerable: true,
   get() {
-    return window.gBrowser.getFindBar();
+    return gBrowser.getCachedFindBar();
   },
 });
 
@@ -274,10 +274,26 @@ Object.defineProperty(this, "gFindBarInitialized", {
   configurable: true,
   enumerable: true,
   get() {
-    return window.gBrowser.isFindBarInitialized();
+    return gBrowser.isFindBarInitialized();
   },
 });
 
+Object.defineProperty(this, "gFindBarPromise", {
+  configurable: true,
+  enumerable: true,
+  get() {
+    return gBrowser.getFindBar();
+  },
+});
+
+async function gLazyFindCommand(cmd, ...args) {
+  let fb = await gFindBarPromise;
+  // We could be closed by now, or the tab with XBL binding could have gone away:
+  if (fb && fb[cmd]) {
+    fb[cmd].apply(fb, args);
+  }
+}
+
 Object.defineProperty(this, "AddonManager", {
   configurable: true,
   enumerable: true,
@@ -2069,7 +2085,7 @@ function HandleAppCommandEvent(evt) {
     BrowserCloseTabOrWindow();
     break;
   case "Find":
-    gFindBar.onFindCommand();
+    gLazyFindCommand("onFindCommand");
     break;
   case "Help":
     openHelpLink("firefox-help");
@@ -3517,7 +3533,7 @@ var PrintPreviewListener = {
       gBrowser.getNotificationBox().notificationsHidden = false;
 
     if (this._chromeState.findOpen)
-      gFindBar.open();
+      gLazyFindCommand("open");
 
     if (this._chromeState.globalNotificationsOpen)
       document.getElementById("global-notificationbox").notificationsHidden = false;

browser/base/content/tabbrowser.js

@@ -477,20 +477,54 @@ window._gBrowser = {
     return (aTab || this.selectedTab)._findBar != undefined;
   },
 
-  getFindBar(aTab) {
-    if (!aTab)
-      aTab = this.selectedTab;
+  /**
+   * Get the already constructed findbar
+   */
+  getCachedFindBar(aTab = this.selectedTab) {
+    return aTab._findBar;
+  },
 
-    if (aTab._findBar)
-      return aTab._findBar;
+  /**
+   * Get the findbar, and create it if it doesn't exist.
+   * @return the find bar (or null if the window or tab is closed/closing in the interim).
+   */
+  async getFindBar(aTab = this.selectedTab) {
+    let findBar = this.getCachedFindBar(aTab);
+    if (findBar) {
+      return findBar;
+    }
 
+    // Avoid re-entrancy by caching the promise we're about to return.
+    if (!aTab._pendingFindBar) {
+      aTab._pendingFindBar = this._createFindBar(aTab);
+    }
+    return aTab._pendingFindBar;
+  },
+
+  /**
+   * Create a findbar instance.
+   * @param aTab the tab to create the find bar for.
+   * @param aForce Whether to force a sync flush to trigger XBL construction immediately.
+   * @return the created findbar, or null if the window or tab is closed/closing.
+   */
+  async _createFindBar(aTab, aForce = false) {
     let findBar = document.createElementNS(this._XUL_NS, "findbar");
     let browser = this.getBrowserForTab(aTab);
     let browserContainer = this.getBrowserContainer(browser);
     browserContainer.appendChild(findBar);
 
-    // Force a style flush to ensure that our binding is attached.
-    findBar.clientTop;
+    if (aForce) {
+      // Force a style flush to ensure that our binding is attached.
+      // Remove after bug 1371523 makes more of this async.
+      findBar.clientTop;
+    } else {
+      await new Promise(r => requestAnimationFrame(r));
+      if (window.closed || aTab.closing) {
+        delete aTab._pendingFindBar;
+        return null;
+      }
+    }
+    delete aTab._pendingFindBar;
 
     findBar.browser = browser;
     findBar._findField.value = this._lastFindValue;
@@ -1097,7 +1131,7 @@ window._gBrowser = {
     oldBrowser._urlbarFocused = (gURLBar && gURLBar.focused);
 
     if (this.isFindBarInitialized(oldTab)) {
-      let findBar = this.getFindBar(oldTab);
+      let findBar = this.getCachedFindBar(oldTab);
       oldTab._findBarFocused = (!findBar.hidden &&
         findBar._findField.getAttribute("focused") == "true");
     }
@@ -1672,7 +1706,7 @@ window._gBrowser = {
 
     // If the findbar has been initialised, reset its browser reference.
     if (this.isFindBarInitialized(tab)) {
-      this.getFindBar(tab).browser = aBrowser;
+      this.getCachedFindBar(tab).browser = aBrowser;
     }
 
     evt = document.createEvent("Events");
@@ -3081,10 +3115,17 @@ window._gBrowser = {
     let otherFindBar = aOtherTab._findBar;
     if (otherFindBar &&
         otherFindBar.findMode == otherFindBar.FIND_NORMAL) {
-      let ourFindBar = this.getFindBar(aOurTab);
-      ourFindBar._findField.value = otherFindBar._findField.value;
-      if (!otherFindBar.hidden)
-        ourFindBar.onFindCommand();
+      let oldValue = otherFindBar._findField.value;
+      let wasHidden = otherFindBar.hidden;
+      let ourFindBarPromise = this.getFindBar(aOurTab);
+      ourFindBarPromise.then(ourFindBar => {
+        if (!ourFindBar) {
+          return;
+        }
+        ourFindBar._findField.value = oldValue;
+        if (!wasHidden)
+          ourFindBar.onFindCommand();
+      });
     }
 
     // Finish tearing down the tab that's going away.
@@ -3791,7 +3832,13 @@ window._gBrowser = {
           }
           if (shouldFastFind) {
             // Make sure we return the result.
-            return this.getFindBar(tab).receiveMessage(aMessage);
+            // This needs sync initialization of the find bar, unfortunately.
+            // bug 1371523 tracks removing all of this.
+
+            // This returns a promise, so don't use the result...
+            this._createFindBar(tab, true);
+            // ... just grab the 'cached' version now we know it exists.
+            this.getCachedFindBar().receiveMessage(aMessage);
           }
         }
         break;
@@ -4489,7 +4536,7 @@ class TabProgressListener {
       }
 
       if (gBrowser.isFindBarInitialized(this.mTab)) {
-        let findBar = gBrowser.getFindBar(this.mTab);
+        let findBar = gBrowser.getCachedFindBar(this.mTab);
 
         // Close the Find toolbar if we're in old-style TAF mode
         if (findBar.findMode != findBar.FIND_NORMAL) {

browser/base/content/test/general/browser_bug537013.js

@@ -42,19 +42,21 @@ function test() {
   // Set up the first tab
   gBrowser.selectedTab = tabs[0];
 
+  gBrowser.getFindBar().then(initialTest);
+}
+
+function initialTest() {
   setFindString(texts[0]);
   // Turn on highlight for testing bug 891638
   gFindBar.getElement("highlight").checked = true;
 
   // Make sure the second tab is correct, then set it up
   gBrowser.selectedTab = tabs[1];
-  gBrowser.selectedTab.addEventListener("TabFindInitialized", continueTests1);
+  gBrowser.selectedTab.addEventListener("TabFindInitialized", continueTests1, {once: true});
   // Initialize the findbar
-  gFindBar;
+  gBrowser.getFindBar();
 }
 function continueTests1() {
-  gBrowser.selectedTab.removeEventListener("TabFindInitialized",
-                                           continueTests1);
   ok(true, "'TabFindInitialized' event properly dispatched!");
   ok(gFindBar.hidden, "Second tab doesn't show find bar!");
   gFindBar.open();
@@ -97,6 +99,11 @@ function continueTests3() {
 
   // Set up a third tab, no tests here
   gBrowser.selectedTab = tabs[2];
+  gBrowser.selectedTab.addEventListener("TabFindInitialized", continueTests4, {once: true});
+  gBrowser.getFindBar();
+}
+
+function continueTests4() {
   setFindString(texts[2]);
 
   // Now we jump to the second, then first, and then fourth

browser/base/content/test/general/browser_bug567306.js

@@ -21,7 +21,7 @@ add_task(async function() {
   await SimpleTest.promiseFocus(newwindow);
 
   ok(!newwindow.gFindBarInitialized, "find bar is not yet initialized");
-  let findBar = newwindow.gFindBar;
+  let findBar = await newwindow.gFindBarPromise;
 
   await ContentTask.spawn(selectedBrowser, { }, async function() {
     let elt = content.document.getElementById("h1");

browser/base/content/test/general/browser_bug749738.js

@@ -6,24 +6,25 @@
 
 const DUMMY_PAGE = "http://example.org/browser/browser/base/content/test/general/dummy_page.html";
 
-function test() {
-  waitForExplicitFinish();
+/**
+ * This test checks that if you search for something on one tab, then close
+ * that tab and have the find bar open on the next tab you get switched to,
+ * closing the find bar in that tab works without exceptions.
+ */
+add_task(async function test_bug749738() {
+  // Open find bar on initial tab.
+  await gFindBarPromise;
 
-  let tab = BrowserTestUtils.addTab(gBrowser);
-  gBrowser.selectedTab = tab;
-
-  BrowserTestUtils.loadURI(tab.linkedBrowser, DUMMY_PAGE);
-  BrowserTestUtils.browserLoaded(tab.linkedBrowser).then(() => {
+  await BrowserTestUtils.withNewTab(DUMMY_PAGE, async function() {
+    await gFindBarPromise;
     gFindBar.onFindCommand();
     EventUtils.sendString("Dummy");
-    gBrowser.removeTab(tab);
-
-    try {
-      gFindBar.close();
-      ok(true, "findbar.close should not throw an exception");
-    } catch (e) {
-      ok(false, "findbar.close threw exception: " + e);
-    }
-    finish();
   });
-}
+
+  try {
+    gFindBar.close();
+    ok(true, "findbar.close should not throw an exception");
+  } catch (e) {
+    ok(false, "findbar.close threw exception: " + e);
+  }
+});

browser/base/content/test/general/browser_findbarClose.js

@@ -16,6 +16,7 @@ add_task(async function findbar_test() {
     "browser/base/content/test/general/test_bug628179.html");
   await promise;
 
+  await gFindBarPromise;
   gFindBar.open();
 
   await new ContentTask.spawn(newTab.linkedBrowser, null, async function() {

browser/base/content/test/general/browser_zbug569342.js

@@ -2,79 +2,60 @@
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
-var gTab = null;
-
-function load(url, cb) {
-  gTab = BrowserTestUtils.addTab(gBrowser, url);
-  gBrowser.addEventListener("load", function listener(event) {
-    if (event.target.location != url)
-      return;
-
-    gBrowser.removeEventListener("load", listener, true);
-    // Trigger onLocationChange by switching tabs.
-    gBrowser.selectedTab = gTab;
-    cb();
-  }, true);
-}
-
-function test() {
-  waitForExplicitFinish();
-
-  ok(gFindBar.hidden, "Find bar should not be visible by default");
+add_task(async function findBarDisabledOnSomePages() {
+  ok(!gFindBar || gFindBar.hidden, "Find bar should not be visible by default");
 
+  let findbarOpenedPromise = BrowserTestUtils.waitForEvent(gBrowser.selectedTab, "TabFindInitialized");
+  document.documentElement.focus();
   // Open the Find bar before we navigate to pages that shouldn't have it.
   EventUtils.synthesizeKey("f", { accelKey: true });
+  await findbarOpenedPromise;
   ok(!gFindBar.hidden, "Find bar should be visible");
 
-  nextTest();
-}
+  let urls = [
+    "about:config",
+    "about:addons",
+  ];
 
-var urls = [
-  "about:config",
-  "about:addons",
-];
-
-function nextTest() {
-  let url = urls.shift();
-  if (url) {
-    testFindDisabled(url, nextTest);
-  } else {
-    // Make sure the find bar is re-enabled after disabled page is closed.
-    testFindEnabled("about:blank", function() {
-      EventUtils.synthesizeKey("KEY_Escape");
-      ok(gFindBar.hidden, "Find bar should now be hidden");
-      finish();
-    });
+  for (let url of urls) {
+    await testFindDisabled(url);
   }
-}
 
-function testFindDisabled(url, cb) {
-  load(url, function() {
-    ok(gFindBar.hidden, "Find bar should not be visible");
-    EventUtils.synthesizeKey("/", {}, gTab.linkedBrowser.contentWindow);
-    ok(gFindBar.hidden, "Find bar should not be visible");
+  // Make sure the find bar is re-enabled after disabled page is closed.
+  await testFindEnabled("about:about");
+  gFindBar.close();
+  ok(gFindBar.hidden, "Find bar should now be hidden");
+});
+
+function testFindDisabled(url) {
+  return BrowserTestUtils.withNewTab(url, async function(browser) {
+    let waitForFindBar = async () => {
+      await new Promise(r => requestAnimationFrame(r));
+      await new Promise(r => Services.tm.dispatchToMainThread(r));
+    };
+    ok(!gFindBar || gFindBar.hidden, "Find bar should not be visible at the start");
+    await BrowserTestUtils.synthesizeKey("/", {}, browser);
+    await waitForFindBar();
+    ok(!gFindBar || gFindBar.hidden, "Find bar should not be visible after fast find");
     EventUtils.synthesizeKey("f", {accelKey: true});
-    ok(gFindBar.hidden, "Find bar should not be visible");
+    await waitForFindBar();
+    ok(!gFindBar || gFindBar.hidden, "Find bar should not be visible after find command");
     ok(document.getElementById("cmd_find").getAttribute("disabled"),
        "Find command should be disabled");
-
-    gBrowser.removeTab(gTab);
-    cb();
   });
 }
 
-function testFindEnabled(url, cb) {
-  load(url, function() {
+async function testFindEnabled(url) {
+  return BrowserTestUtils.withNewTab(url, async function(browser) {
     ok(!document.getElementById("cmd_find").getAttribute("disabled"),
        "Find command should not be disabled");
 
     // Open Find bar and then close it.
+    let findbarOpenedPromise = BrowserTestUtils.waitForEvent(gBrowser.selectedTab, "TabFindInitialized");
     EventUtils.synthesizeKey("f", { accelKey: true });
+    await findbarOpenedPromise;
     ok(!gFindBar.hidden, "Find bar should be visible again");
     EventUtils.synthesizeKey("KEY_Escape");
     ok(gFindBar.hidden, "Find bar should now be hidden");
-
-    gBrowser.removeTab(gTab);
-    cb();
   });
 }

browser/base/content/test/sanitize/browser_sanitize-formhistory.js

@@ -22,6 +22,7 @@ add_task(async function test() {
 
   // Sanitize now so we can test the baseline point.
   await Sanitizer.sanitize(["formdata"]);
+  await gFindBarPromise;
   ok(!gFindBar.hasTransactions, "pre-test baseline for sanitizer");
 
   gFindBar.getElement("findbar-textbox").value = "m";

browser/components/customizableui/CustomizableWidgets.jsm

@@ -181,8 +181,8 @@ const CustomizableWidgets = [
     tooltiptext: "find-button.tooltiptext3",
     onCommand(aEvent) {
       let win = aEvent.target.ownerGlobal;
-      if (win.gFindBar) {
-        win.gFindBar.onFindCommand();
+      if (win.gLazyFindCommand) {
+        win.gLazyFindCommand("onFindCommand");
       }
     }
   }, {

browser/components/customizableui/test/browser_947914_button_find.js

@@ -17,7 +17,11 @@ add_task(async function() {
   let findButton = document.getElementById("find-button");
   ok(findButton, "Find button exists in Panel Menu");
 
+  let findBarPromise = gBrowser.isFindBarInitialized() ?
+    null : BrowserTestUtils.waitForEvent(gBrowser.selectedTab, "TabFindInitialized");
+
   findButton.click();
+  await findBarPromise;
   ok(!gFindBar.hasAttribute("hidden"), "Findbar opened successfully");
 
   // close find bar

browser/components/customizableui/test/browser_panel_keyboard_navigation.js

@@ -94,12 +94,15 @@ add_task(async function testEnterKeyBehaviors() {
     EventUtils.synthesizeKey("KEY_ArrowUp");
     focusedElement = document.commandDispatcher.focusedElement;
   }
+  let findBarPromise = gBrowser.isFindBarInitialized() ?
+    null : BrowserTestUtils.waitForEvent(gBrowser.selectedTab, "TabFindInitialized");
   Assert.equal(focusedElement.id, kFindButtonId, "Find button should be selected");
 
   promise = promisePanelHidden(window);
   EventUtils.synthesizeKey("KEY_Enter");
   await promise;
 
+  await findBarPromise;
   Assert.ok(!gFindBar.hidden, "Findbar should have opened");
   gFindBar.close();
 });

browser/components/uitour/test/browser_UITour_panel_close_annotation.js

@@ -16,7 +16,10 @@ var tooltip = document.getElementById("UITourTooltip");
 function test() {
   registerCleanupFunction(() => {
     // Close the find bar in case it's open in the remaining tab
-    gBrowser.getFindBar(gBrowser.selectedTab).close();
+    let findBar = gBrowser.getCachedFindBar(gBrowser.selectedTab);
+    if (findBar) {
+      findBar.close();
+    }
   });
   UITourTest();
 }

browser/modules/Sanitizer.jsm

@@ -494,7 +494,7 @@ var Sanitizer = {
             }
             for (let tab of tabBrowser.tabs) {
               if (tabBrowser.isFindBarInitialized(tab))
-                tabBrowser.getFindBar(tab).clear();
+                tabBrowser.getCachedFindBar(tab).clear();
             }
             // Clear any saved find value
             tabBrowser._lastFindValue = "";

devtools/client/responsive.html/browser/swap.js

@@ -188,7 +188,7 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
       // Swapping browsers disconnects the find bar UI from the browser.
       // If the find bar has been initialized, reconnect it.
       if (gBrowser.isFindBarInitialized(tab)) {
-        let findBar = gBrowser.getFindBar(tab);
+        let findBar = gBrowser.getCachedFindBar(tab);
         findBar.browser = tab.linkedBrowser;
         if (!findBar.hidden) {
           // Force the find bar to activate again, restoring the search string.
@@ -253,7 +253,7 @@ function swapToInnerBrowser({ tab, containerURL, getInnerBrowser }) {
       // Swapping browsers disconnects the find bar UI from the browser.
       // If the find bar has been initialized, reconnect it.
       if (gBrowser.isFindBarInitialized(tab)) {
-        let findBar = gBrowser.getFindBar(tab);
+        let findBar = gBrowser.getCachedFindBar(tab);
         findBar.browser = tab.linkedBrowser;
         if (!findBar.hidden) {
           // Force the find bar to activate again, restoring the search string.

toolkit/content/tests/browser/browser_bug1198465.js

@@ -26,6 +26,11 @@ add_task(async function() {
   //    browser has dispatched its return message with the prefill value for
   //    the findbar, which essentially nulls these tests.
 
+  // The parent-side of the sidebar initialization is also async, so we do
+  // need to wait for that. We verify a bit further down that _startFindDeferred
+  // hasn't been resolved yet.
+  await gFindBarPromise;
+
   let findBar = gFindBar;
   is(findBar._findField.value, "", "findbar is empty");
 

toolkit/content/tests/browser/browser_bug451286.js

@@ -135,6 +135,7 @@ function findAgainAndWait() {
 }
 
 async function openFindBarAndWait() {
+  await gFindBarPromise;
   let awaitTransitionEnd = BrowserTestUtils.waitForEvent(gFindBar, "transitionend");
   gFindBar.open();
   await awaitTransitionEnd;

toolkit/content/tests/browser/browser_bug982298.js

@@ -20,6 +20,7 @@ add_task(async function() {
       info("about to add results listener, open find bar, and send 'F' string");
       browser.finder.addResultListener(listener);
     });
+    await gFindBarPromise;
     gFindBar.onFindCommand();
     EventUtils.sendString("F");
     info("added result listener and sent string 'F'");

toolkit/content/tests/browser/browser_findbar.js

@@ -17,7 +17,7 @@ add_task(async function test_hotkey_event_propagation() {
   // Opening new tab
   let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_PAGE_URI);
   let browser = gBrowser.getBrowserForTab(tab);
-  let findbar = gBrowser.getFindBar();
+  let findbar = await gBrowser.getFindBar();
 
   // Pressing these keys open the findbar.
   const HOTKEYS = ["/", "'"];
@@ -64,7 +64,7 @@ add_task(async function test_not_found() {
 
   // Search for the first word.
   await promiseFindFinished("--- THIS SHOULD NEVER MATCH ---", false);
-  let findbar = gBrowser.getFindBar();
+  let findbar = gBrowser.getCachedFindBar();
   is(findbar._findStatusDesc.textContent, findbar._notFoundStr,
      "Findbar status text should be 'Phrase not found'");
 
@@ -76,7 +76,7 @@ add_task(async function test_found() {
 
   // Search for a string that WILL be found, with 'Highlight All' on
   await promiseFindFinished("S", true);
-  ok(!gBrowser.getFindBar()._findStatusDesc.textContent,
+  ok(!gBrowser.getCachedFindBar()._findStatusDesc.textContent,
      "Findbar status should be empty");
 
   gBrowser.removeTab(tab);
@@ -86,10 +86,10 @@ add_task(async function test_found() {
 // new tab find bar.
 add_task(async function test_tabwise_case_sensitive() {
   let tab1 = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_PAGE_URI);
-  let findbar1 = gBrowser.getFindBar();
+  let findbar1 = await gBrowser.getFindBar();
 
   let tab2 = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_PAGE_URI);
-  let findbar2 = gBrowser.getFindBar();
+  let findbar2 = await gBrowser.getFindBar();
 
   // Toggle case sensitivity for first findbar
   findbar1.getElement("find-case-sensitive").click();
@@ -130,7 +130,7 @@ add_task(async function test_reinitialization_at_remoteness_change() {
   // Load a remote page and trigger findbar construction.
   let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_PAGE_URI);
   let browser = gBrowser.getBrowserForTab(tab);
-  let findbar = gBrowser.getFindBar();
+  let findbar = await gBrowser.getFindBar();
 
   // Findbar should operate normally.
   await promiseFindFinished("z", false);
@@ -173,6 +173,7 @@ add_task(async function() {
 
   ok(!gFindBarInitialized, "findbar isn't initialized yet");
 
+  await gFindBarPromise;
   let findBar = gFindBar;
   let initialValue = findBar._findField.value;
 
@@ -199,9 +200,9 @@ add_task(async function() {
 });
 
 function promiseFindFinished(searchText, highlightOn) {
-  return new Promise(resolve => {
+  return new Promise(async (resolve) => {
 
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
     findbar.startFind(findbar.FIND_NORMAL);
     let highlightElement = findbar.getElement("highlight");
     if (highlightElement.checked != highlightOn)

toolkit/content/tests/browser/browser_quickfind_editable.js

@@ -3,7 +3,7 @@ const DESIGNMODE_PAGE = "data:text/html,<body onload='document.designMode=\"on\"
 const HOTKEYS = ["/", "'"];
 
 async function test_hotkeys(browser, expected) {
-  let findbar = gBrowser.getFindBar();
+  let findbar = await gBrowser.getFindBar();
   for (let key of HOTKEYS) {
     is(findbar.hidden, true, "findbar is hidden");
     await BrowserTestUtils.sendChar(key, gBrowser.selectedBrowser);

toolkit/content/widgets/findbar.xml

@@ -420,7 +420,7 @@
             return;
           this._destroyed = true;
 
-          if (this.browser.finder)
+          if (this.browser && this.browser.finder)
             this.browser.finder.destroy();
 
           this.browser = null;

toolkit/modules/tests/browser/browser_FinderHighlighter.js

@@ -49,7 +49,7 @@ add_task(async function testModalResults() {
   ]);
   let url = kFixtureBaseURL + "file_FinderSample.html";
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
 
     for (let [word, expectedResult] of tests) {
       await promiseOpenFindbar(findbar);
@@ -76,7 +76,7 @@ add_task(async function testModalResults() {
 add_task(async function testModalSwitching() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
 
     await promiseOpenFindbar(findbar);
     Assert.ok(!findbar.hidden, "Findbar should be open now.");
@@ -113,7 +113,7 @@ add_task(async function testModalSwitching() {
 add_task(async function testDarkPageDetection() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
 
     await promiseOpenFindbar(findbar);
 
@@ -134,7 +134,7 @@ add_task(async function testDarkPageDetection() {
   });
 
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
 
     await promiseOpenFindbar(findbar);
 
@@ -172,7 +172,7 @@ add_task(async function testDarkPageDetection() {
 add_task(async function testHighlightAllToggle() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
 
     await promiseOpenFindbar(findbar);
 
@@ -216,7 +216,7 @@ add_task(async function testXMLDocument() {
   <Error>Error</Error>
 </result>`);
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
 
     await promiseOpenFindbar(findbar);
 
@@ -238,7 +238,7 @@ add_task(async function testHideOnLocationChange() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, url);
   let browser = tab.linkedBrowser;
-  let findbar = gBrowser.getFindBar();
+  let findbar = await gBrowser.getFindBar();
 
   await promiseOpenFindbar(findbar);
 
@@ -267,7 +267,7 @@ add_task(async function testHideOnLocationChange() {
 add_task(async function testHideOnClear() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
     await promiseOpenFindbar(findbar);
 
     let word = "Roland";
@@ -299,7 +299,7 @@ add_task(async function testRectsAndTexts() {
     "Here are a lot of words Please use find to highlight some words that wrap" +
     " across a line boundary and see what happens.</div>");
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
     await promiseOpenFindbar(findbar);
 
     let word = "words please use find to";
@@ -322,7 +322,7 @@ add_task(async function testRectsAndTexts() {
 add_task(async function testTooLargeToggle() {
   let url = kFixtureBaseURL + "file_FinderSample.html";
   await BrowserTestUtils.withNewTab(url, async function(browser) {
-    let findbar = gBrowser.getFindBar();
+    let findbar = await gBrowser.getFindBar();
     await promiseOpenFindbar(findbar);
 
     await ContentTask.spawn(browser, null, async function() {

toolkit/modules/tests/browser/head.js

@@ -25,7 +25,8 @@ function compareLists(list1, list2, kind) {
   is(String(list1), String(list2), `${kind} URLs correct`);
 }
 
-function promiseOpenFindbar(findbar) {
+async function promiseOpenFindbar(findbar) {
+  await gBrowser.getFindBar();
   findbar.onFindCommand();
   return gFindBar._startFindDeferred && gFindBar._startFindDeferred.promise;
 }