Bug 1321215 - Remove legacy generator from browser/. r=Paolo

browser/base/content/test/chrome/test_aboutCrashed.xul

@@ -16,42 +16,38 @@
     const Cu = Components.utils;
 
     Cu.import("resource://gre/modules/Services.jsm");
-    Cu.import("resource://gre/modules/Task.jsm");
-    Cu.import("resource://gre/modules/Promise.jsm");
     Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
     SimpleTest.waitForExplicitFinish();
 
     // Load error pages do not fire "load" events, so let's use a progressListener.
     function waitForErrorPage(frame) {
-      let errorPageDeferred = Promise.defer();
+      return new Promise(resolve => {
+        let progressListener = {
+          onLocationChange: function(aWebProgress, aRequest, aLocation, aFlags) {
+            if (aFlags & Ci.nsIWebProgressListener.LOCATION_CHANGE_ERROR_PAGE) {
+              frame.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
+                            .getInterface(Ci.nsIWebProgress)
+                            .removeProgressListener(progressListener,
+                                                    Ci.nsIWebProgress.NOTIFY_LOCATION);
 
-      let progressListener = {
-        onLocationChange: function(aWebProgress, aRequest, aLocation, aFlags) {
-          if (aFlags & Ci.nsIWebProgressListener.LOCATION_CHANGE_ERROR_PAGE) {
-            frame.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
-                          .getInterface(Ci.nsIWebProgress)
-                          .removeProgressListener(progressListener,
-                                                  Ci.nsIWebProgress.NOTIFY_LOCATION);
+              resolve();
+            }
+          },
 
-            errorPageDeferred.resolve();
-          }
-        },
+          QueryInterface: XPCOMUtils.generateQI([Ci.nsIWebProgressListener,
+                                                 Ci.nsISupportsWeakReference])
+        };
 
-        QueryInterface: XPCOMUtils.generateQI([Ci.nsIWebProgressListener,
-                                               Ci.nsISupportsWeakReference])
-      };
-
-      frame.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
-                    .getInterface(Ci.nsIWebProgress)
-                    .addProgressListener(progressListener,
-                                         Ci.nsIWebProgress.NOTIFY_LOCATION);
-
-      return errorPageDeferred.promise;
+        frame.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
+                      .getInterface(Ci.nsIWebProgress)
+                      .addProgressListener(progressListener,
+                                           Ci.nsIWebProgress.NOTIFY_LOCATION);
+      });
     }
 
   function doTest() {
-    Task.spawn(function test_aboutCrashed() {
+    (async function testBody() {
       let frame1 = document.getElementById("frame1");
       let frame2 = document.getElementById("frame2");
       let uri1 = Services.io.newURI("http://www.example.com/1", null, null);
@@ -61,7 +57,7 @@
       frame1.docShell.chromeEventHandler.setAttribute("crashedPageTitle", "pageTitle");
       frame1.docShell.displayLoadError(Components.results.NS_ERROR_CONTENT_CRASHED, uri1, null);
 
-      yield errorPageReady;
+      await errorPageReady;
       frame1.docShell.chromeEventHandler.removeAttribute("crashedPageTitle");
 
       SimpleTest.is(frame1.contentDocument.documentURI,
@@ -71,14 +67,14 @@
       errorPageReady = waitForErrorPage(frame2);
       frame2.docShell.displayLoadError(Components.results.NS_ERROR_CONTENT_CRASHED, uri2, null);
 
-      yield errorPageReady;
+      await errorPageReady;
 
       SimpleTest.is(frame2.contentDocument.documentURI,
                     "about:tabcrashed?e=tabcrashed&u=http%3A//www.example.com/2&c=UTF-8&f=regular&d=%20",
                     "Correct about:tabcrashed displayed for page with no title.");
 
       SimpleTest.finish();
-  });
+    })().catch(ex => SimpleTest.ok(false, ex));
   }
   ]]></script>
 

browser/components/downloads/test/browser/browser_libraryDrop.js

@@ -17,17 +17,17 @@ add_task(function* test_indicatorDrop() {
   let EventUtils = {};
   scriptLoader.loadSubScript("chrome://mochikit/content/tests/SimpleTest/EventUtils.js", EventUtils);
 
-  function task_drop(win, urls) {
+  async function drop(win, urls) {
     let dragData = [[{type: "text/plain", data: urls.join("\n")}]];
 
     let listBox = win.document.getElementById("downloadsRichListBox");
     ok(listBox, "download list box present");
 
-    let list = yield Downloads.getList(Downloads.ALL);
+    let list = await Downloads.getList(Downloads.ALL);
 
     let added = new Set();
     let succeeded = new Set();
-    yield new Promise(function(resolve) {
+    await new Promise(resolve => {
       let view = {
         onDownloadAdded: function(download) {
           added.add(download.source.url);
@@ -65,8 +65,8 @@ add_task(function* test_indicatorDrop() {
     win.close();
   });
 
-  yield* task_drop(win, [httpUrl("file1.txt")]);
-  yield* task_drop(win, [httpUrl("file1.txt"),
-                         httpUrl("file2.txt"),
-                         httpUrl("file3.txt")]);
+  yield drop(win, [httpUrl("file1.txt")]);
+  yield drop(win, [httpUrl("file1.txt"),
+                   httpUrl("file2.txt"),
+                   httpUrl("file3.txt")]);
 });

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_DownloadLastDirWithCPS.js

@@ -7,8 +7,7 @@ var gTests;
 function test() {
   waitForExplicitFinish();
   requestLongerTimeout(2);
-  gTests = runTest();
-  gTests.next();
+  runTest().catch(ex => ok(false, ex));
 }
 
 /*
@@ -17,34 +16,22 @@ function test() {
  * ================
  */
 
-function moveAlong(aResult) {
-  try {
-    gTests.send(aResult);
-  } catch (x if x instanceof StopIteration) {
-    finish();
-  }
-}
-
 function createWindow(aOptions) {
-  whenNewWindowLoaded(aOptions, function(win) {
-    moveAlong(win);
-  });
+  return new Promise(resolve => whenNewWindowLoaded(aOptions, resolve));
 }
 
 function getFile(downloadLastDir, aURI) {
-  downloadLastDir.getFileAsync(aURI, function(result) {
-    moveAlong(result);
-  });
+  return new Promise(resolve => downloadLastDir.getFileAsync(aURI, resolve));
 }
 
 function setFile(downloadLastDir, aURI, aValue) {
   downloadLastDir.setFile(aURI, aValue);
-  executeSoon(moveAlong);
+  return new Promise(resolve => executeSoon(resolve));
 }
 
 function clearHistoryAndWait() {
   clearHistory();
-  executeSoon(() => executeSoon(moveAlong));
+  return new Promise(resolve => executeSoon(_ => executeSoon(resolve)));
 }
 
 /*
@@ -53,7 +40,7 @@ function clearHistoryAndWait() {
  * ===================
  */
 
-function runTest() {
+async function runTest() {
   let FileUtils =
     Cu.import("resource://gre/modules/FileUtils.jsm", {}).FileUtils;
   let DownloadLastDir =
@@ -81,12 +68,12 @@ function runTest() {
   function checkDownloadLastDir(gDownloadLastDir, aLastDir) {
     is(gDownloadLastDir.file.path, aLastDir.path,
        "gDownloadLastDir should point to the expected last directory");
-    getFile(gDownloadLastDir, uri1);
+    return getFile(gDownloadLastDir, uri1);
   }
 
   function checkDownloadLastDirNull(gDownloadLastDir) {
     is(gDownloadLastDir.file, null, "gDownloadLastDir should be null");
-    getFile(gDownloadLastDir, uri1);
+    return getFile(gDownloadLastDir, uri1);
   }
 
   /*
@@ -95,8 +82,8 @@ function runTest() {
    * ================================
    */
 
-  let win = yield createWindow({private: false});
-  let pbWin = yield createWindow({private: true});
+  let win = await createWindow({private: false});
+  let pbWin = await createWindow({private: true});
 
   let downloadLastDir = new DownloadLastDir(win);
   let pbDownloadLastDir = new DownloadLastDir(pbWin);
@@ -113,7 +100,7 @@ function runTest() {
      "LastDir pref should be null to start with");
 
   // set up last dir
-  yield setFile(downloadLastDir, null, tmpDir);
+  await setFile(downloadLastDir, null, tmpDir);
   is(downloadLastDir.file.path, tmpDir.path,
      "LastDir should point to the tmpDir");
   isnot(downloadLastDir.file, tmpDir,
@@ -121,111 +108,111 @@ function runTest() {
 
   // set uri1 to dir1, all should now return dir1
   // also check that a new object is returned
-  yield setFile(downloadLastDir, uri1, dir1);
+  await setFile(downloadLastDir, uri1, dir1);
   is(downloadLastDir.file.path, dir1.path,
      "downloadLastDir should return dir1");
   isnot(downloadLastDir.file, dir1,
         "downloadLastDir.file should not return dir1");
-  is((yield getFile(downloadLastDir, uri1)).path, dir1.path,
+  is((await getFile(downloadLastDir, uri1)).path, dir1.path,
      "uri1 should return dir1"); // set in CPS
-  isnot((yield getFile(downloadLastDir, uri1)), dir1,
+  isnot((await getFile(downloadLastDir, uri1)), dir1,
         "getFile on uri1 should not return dir1");
-  is((yield getFile(downloadLastDir, uri2)).path, dir1.path,
+  is((await getFile(downloadLastDir, uri2)).path, dir1.path,
      "uri2 should return dir1"); // fallback
-  isnot((yield getFile(downloadLastDir, uri2)), dir1,
+  isnot((await getFile(downloadLastDir, uri2)), dir1,
         "getFile on uri2 should not return dir1");
-  is((yield getFile(downloadLastDir, uri3)).path, dir1.path,
+  is((await getFile(downloadLastDir, uri3)).path, dir1.path,
      "uri3 should return dir1"); // fallback
-  isnot((yield getFile(downloadLastDir, uri3)), dir1,
+  isnot((await getFile(downloadLastDir, uri3)), dir1,
         "getFile on uri3 should not return dir1");
-  is((yield getFile(downloadLastDir, uri4)).path, dir1.path,
+  is((await getFile(downloadLastDir, uri4)).path, dir1.path,
      "uri4 should return dir1"); // fallback
-  isnot((yield getFile(downloadLastDir, uri4)), dir1,
+  isnot((await getFile(downloadLastDir, uri4)), dir1,
         "getFile on uri4 should not return dir1");
 
   // set uri2 to dir2, all except uri1 should now return dir2
-  yield setFile(downloadLastDir, uri2, dir2);
+  await setFile(downloadLastDir, uri2, dir2);
   is(downloadLastDir.file.path, dir2.path,
      "downloadLastDir should point to dir2");
-  is((yield getFile(downloadLastDir, uri1)).path, dir1.path,
+  is((await getFile(downloadLastDir, uri1)).path, dir1.path,
      "uri1 should return dir1"); // set in CPS
-  is((yield getFile(downloadLastDir, uri2)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri2)).path, dir2.path,
      "uri2 should return dir2"); // set in CPS
-  is((yield getFile(downloadLastDir, uri3)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri3)).path, dir2.path,
      "uri3 should return dir2"); // fallback
-  is((yield getFile(downloadLastDir, uri4)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri4)).path, dir2.path,
      "uri4 should return dir2"); // fallback
 
   // set uri3 to dir3, all except uri1 and uri2 should now return dir3
-  yield setFile(downloadLastDir, uri3, dir3);
+  await setFile(downloadLastDir, uri3, dir3);
   is(downloadLastDir.file.path, dir3.path,
      "downloadLastDir should point to dir3");
-  is((yield getFile(downloadLastDir, uri1)).path, dir1.path,
+  is((await getFile(downloadLastDir, uri1)).path, dir1.path,
      "uri1 should return dir1"); // set in CPS
-  is((yield getFile(downloadLastDir, uri2)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri2)).path, dir2.path,
      "uri2 should return dir2"); // set in CPS
-  is((yield getFile(downloadLastDir, uri3)).path, dir3.path,
+  is((await getFile(downloadLastDir, uri3)).path, dir3.path,
      "uri3 should return dir3"); // set in CPS
-  is((yield getFile(downloadLastDir, uri4)).path, dir3.path,
+  is((await getFile(downloadLastDir, uri4)).path, dir3.path,
      "uri4 should return dir4"); // fallback
 
   // set uri1 to dir2, all except uri3 should now return dir2
-  yield setFile(downloadLastDir, uri1, dir2);
+  await setFile(downloadLastDir, uri1, dir2);
   is(downloadLastDir.file.path, dir2.path,
      "downloadLastDir should point to dir2");
-  is((yield getFile(downloadLastDir, uri1)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri1)).path, dir2.path,
      "uri1 should return dir2"); // set in CPS
-  is((yield getFile(downloadLastDir, uri2)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri2)).path, dir2.path,
      "uri2 should return dir2"); // set in CPS
-  is((yield getFile(downloadLastDir, uri3)).path, dir3.path,
+  is((await getFile(downloadLastDir, uri3)).path, dir3.path,
      "uri3 should return dir3"); // set in CPS
-  is((yield getFile(downloadLastDir, uri4)).path, dir2.path,
+  is((await getFile(downloadLastDir, uri4)).path, dir2.path,
      "uri4 should return dir2"); // fallback
 
-  yield clearHistoryAndWait();
+  await clearHistoryAndWait();
 
   // check clearHistory removes all data
   is(downloadLastDir.file, null, "clearHistory removes all data");
   //is(Services.contentPrefs.hasPref(uri1, "browser.download.lastDir", null),
   //   false, "LastDir preference should be absent");
-  is((yield getFile(downloadLastDir, uri1)), null, "uri1 should point to null");
-  is((yield getFile(downloadLastDir, uri2)), null, "uri2 should point to null");
-  is((yield getFile(downloadLastDir, uri3)), null, "uri3 should point to null");
-  is((yield getFile(downloadLastDir, uri4)), null, "uri4 should point to null");
+  is((await getFile(downloadLastDir, uri1)), null, "uri1 should point to null");
+  is((await getFile(downloadLastDir, uri2)), null, "uri2 should point to null");
+  is((await getFile(downloadLastDir, uri3)), null, "uri3 should point to null");
+  is((await getFile(downloadLastDir, uri4)), null, "uri4 should point to null");
 
-  yield setFile(downloadLastDir, null, tmpDir);
+  await setFile(downloadLastDir, null, tmpDir);
 
   // check data set outside PB mode is remembered
-  is((yield checkDownloadLastDir(pbDownloadLastDir, tmpDir)).path, tmpDir.path, "uri1 should return the expected last directory");
-  is((yield checkDownloadLastDir(downloadLastDir, tmpDir)).path, tmpDir.path, "uri1 should return the expected last directory");
-  yield clearHistoryAndWait();
+  is((await checkDownloadLastDir(pbDownloadLastDir, tmpDir)).path, tmpDir.path, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDir(downloadLastDir, tmpDir)).path, tmpDir.path, "uri1 should return the expected last directory");
+  await clearHistoryAndWait();
 
-  yield setFile(downloadLastDir, uri1, dir1);
+  await setFile(downloadLastDir, uri1, dir1);
 
   // check data set using CPS outside PB mode is remembered
-  is((yield checkDownloadLastDir(pbDownloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
-  is((yield checkDownloadLastDir(downloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
-  yield clearHistoryAndWait();
+  is((await checkDownloadLastDir(pbDownloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDir(downloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
+  await clearHistoryAndWait();
 
   // check data set inside PB mode is forgotten
-  yield setFile(pbDownloadLastDir, null, tmpDir);
+  await setFile(pbDownloadLastDir, null, tmpDir);
 
-  is((yield checkDownloadLastDir(pbDownloadLastDir, tmpDir)).path, tmpDir.path, "uri1 should return the expected last directory");
-  is((yield checkDownloadLastDirNull(downloadLastDir)), null, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDir(pbDownloadLastDir, tmpDir)).path, tmpDir.path, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDirNull(downloadLastDir)), null, "uri1 should return the expected last directory");
 
-  yield clearHistoryAndWait();
+  await clearHistoryAndWait();
 
   // check data set using CPS inside PB mode is forgotten
-  yield setFile(pbDownloadLastDir, uri1, dir1);
+  await setFile(pbDownloadLastDir, uri1, dir1);
 
-  is((yield checkDownloadLastDir(pbDownloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
-  is((yield checkDownloadLastDirNull(downloadLastDir)), null, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDir(pbDownloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDirNull(downloadLastDir)), null, "uri1 should return the expected last directory");
 
   // check data set outside PB mode but changed inside is remembered correctly
-  yield setFile(downloadLastDir, uri1, dir1);
-  yield setFile(pbDownloadLastDir, uri1, dir2);
-  is((yield checkDownloadLastDir(pbDownloadLastDir, dir2)).path, dir2.path, "uri1 should return the expected last directory");
-  is((yield checkDownloadLastDir(downloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
+  await setFile(downloadLastDir, uri1, dir1);
+  await setFile(pbDownloadLastDir, uri1, dir2);
+  is((await checkDownloadLastDir(pbDownloadLastDir, dir2)).path, dir2.path, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDir(downloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
 
   /*
    * ====================
@@ -236,47 +223,49 @@ function runTest() {
   // check that the last dir store got cleared in a new PB window
   pbWin.close();
   // And give it time to close
-  executeSoon(moveAlong);
-  yield;
-  pbWin = yield createWindow({private: true});
+  await new Promise(resolve => executeSoon(resolve));
+
+  pbWin = await createWindow({private: true});
   pbDownloadLastDir = new DownloadLastDir(pbWin);
 
-  is((yield checkDownloadLastDir(pbDownloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDir(pbDownloadLastDir, dir1)).path, dir1.path, "uri1 should return the expected last directory");
 
-  yield clearHistoryAndWait();
+  await clearHistoryAndWait();
 
   // check clearHistory inside PB mode clears data outside PB mode
-  yield setFile(pbDownloadLastDir, uri1, dir2);
+  await setFile(pbDownloadLastDir, uri1, dir2);
 
-  yield clearHistoryAndWait();
+  await clearHistoryAndWait();
 
-  is((yield checkDownloadLastDirNull(downloadLastDir)), null, "uri1 should return the expected last directory");
-  is((yield checkDownloadLastDirNull(pbDownloadLastDir)), null, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDirNull(downloadLastDir)), null, "uri1 should return the expected last directory");
+  is((await checkDownloadLastDirNull(pbDownloadLastDir)), null, "uri1 should return the expected last directory");
 
   // check that disabling CPS works
   Services.prefs.setBoolPref("browser.download.lastDir.savePerSite", false);
 
-  yield setFile(downloadLastDir, uri1, dir1);
+  await setFile(downloadLastDir, uri1, dir1);
   is(downloadLastDir.file.path, dir1.path, "LastDir should be set to dir1");
-  is((yield getFile(downloadLastDir, uri1)).path, dir1.path, "uri1 should return dir1");
-  is((yield getFile(downloadLastDir, uri2)).path, dir1.path, "uri2 should return dir1");
-  is((yield getFile(downloadLastDir, uri3)).path, dir1.path, "uri3 should return dir1");
-  is((yield getFile(downloadLastDir, uri4)).path, dir1.path, "uri4 should return dir1");
+  is((await getFile(downloadLastDir, uri1)).path, dir1.path, "uri1 should return dir1");
+  is((await getFile(downloadLastDir, uri2)).path, dir1.path, "uri2 should return dir1");
+  is((await getFile(downloadLastDir, uri3)).path, dir1.path, "uri3 should return dir1");
+  is((await getFile(downloadLastDir, uri4)).path, dir1.path, "uri4 should return dir1");
 
   downloadLastDir.setFile(uri2, dir2);
   is(downloadLastDir.file.path, dir2.path, "LastDir should be set to dir2");
-  is((yield getFile(downloadLastDir, uri1)).path, dir2.path, "uri1 should return dir2");
-  is((yield getFile(downloadLastDir, uri2)).path, dir2.path, "uri2 should return dir2");
-  is((yield getFile(downloadLastDir, uri3)).path, dir2.path, "uri3 should return dir2");
-  is((yield getFile(downloadLastDir, uri4)).path, dir2.path, "uri4 should return dir2");
+  is((await getFile(downloadLastDir, uri1)).path, dir2.path, "uri1 should return dir2");
+  is((await getFile(downloadLastDir, uri2)).path, dir2.path, "uri2 should return dir2");
+  is((await getFile(downloadLastDir, uri3)).path, dir2.path, "uri3 should return dir2");
+  is((await getFile(downloadLastDir, uri4)).path, dir2.path, "uri4 should return dir2");
 
   Services.prefs.clearUserPref("browser.download.lastDir.savePerSite");
 
   // check that passing null to setFile clears the stored value
-  yield setFile(downloadLastDir, uri3, dir3);
-  is((yield getFile(downloadLastDir, uri3)).path, dir3.path, "LastDir should be set to dir3");
-  yield setFile(downloadLastDir, uri3, null);
-  is((yield getFile(downloadLastDir, uri3)), null, "uri3 should return null");
+  await setFile(downloadLastDir, uri3, dir3);
+  is((await getFile(downloadLastDir, uri3)).path, dir3.path, "LastDir should be set to dir3");
+  await setFile(downloadLastDir, uri3, null);
+  is((await getFile(downloadLastDir, uri3)), null, "uri3 should return null");
 
-  yield clearHistoryAndWait();
+  await clearHistoryAndWait();
+
+  finish();
 }

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_concurrent.js

@@ -17,7 +17,7 @@ add_task(function* setup() {
   });
 });
 
-add_task(function test() {
+add_task(function* test() {
   let prefix = 'http://mochi.test:8888/browser/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_concurrent_page.html';
 
   function getElts(browser) {

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_crh.js

@@ -5,7 +5,7 @@
 // This test makes sure that the Clear Recent History menu item and command 
 // is disabled inside the private browsing mode.
 
-add_task(function test() {
+add_task(function* test() {
   function checkDisableOption(aPrivateMode, aWindow) {
     let crhCommand = aWindow.document.getElementById("Tools:Sanitize");
     ok(crhCommand, "The clear recent history command should exist");

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_downloadLastDir_toggle.js

@@ -75,31 +75,29 @@ add_task(function* test_downloads_last_dir_toggle() {
  *
  * @returns Promise
  */
-function testHelper(options) {
-  return new Task.spawn(function() {
-    let win = yield BrowserTestUtils.openNewBrowserWindow(options);
-    let gDownloadLastDir = new DownloadLastDir(win);
+async function testHelper(options) {
+  let win = await BrowserTestUtils.openNewBrowserWindow(options);
+  let gDownloadLastDir = new DownloadLastDir(win);
 
-    if (options.clearHistory) {
-      clearHistory();
-    }
+  if (options.clearHistory) {
+    clearHistory();
+  }
 
-    if (options.setDir) {
-      gDownloadLastDir.file = options.setDir;
-    }
+  if (options.setDir) {
+    gDownloadLastDir.file = options.setDir;
+  }
 
-    let expectedDir = options.expectedDir;
+  let expectedDir = options.expectedDir;
 
-    if (expectedDir) {
-      is(gDownloadLastDir.file.path, expectedDir.path,
-         "gDownloadLastDir should point to the expected last directory");
-      isnot(gDownloadLastDir.file, expectedDir,
-            "gDownloadLastDir.file should not be pointing to the last directory");
-    } else {
-      is(gDownloadLastDir.file, null, "gDownloadLastDir should be null");
-    }
+  if (expectedDir) {
+    is(gDownloadLastDir.file.path, expectedDir.path,
+       "gDownloadLastDir should point to the expected last directory");
+    isnot(gDownloadLastDir.file, expectedDir,
+          "gDownloadLastDir.file should not be pointing to the last directory");
+  } else {
+    is(gDownloadLastDir.file, null, "gDownloadLastDir should be null");
+  }
 
-    gDownloadLastDir.cleanupPrivateFile();
-    yield BrowserTestUtils.closeWindow(win);
-  });
+  gDownloadLastDir.cleanupPrivateFile();
+  await BrowserTestUtils.closeWindow(win);
 }

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_localStorage.js

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
- add_task(function test() {
+ add_task(function* test() {
   requestLongerTimeout(2);
   const page1 = 'http://mochi.test:8888/browser/browser/components/privatebrowsing/test/browser/' +
                 'browser_privatebrowsing_localStorage_page1.html'

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_localStorage_before_after.js

@@ -10,7 +10,7 @@
 // Step 2: Load the same page in a non-private tab, ensuring that the storage instance reports only one item
 //   existing.
 
-add_task(function test() {
+add_task(function* test() {
   let testURI = "about:blank";
   let prefix = 'http://mochi.test:8888/browser/browser/components/privatebrowsing/test/browser/';
 

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_windowtitle.js

@@ -5,7 +5,7 @@
 // This test makes sure that the window title changes correctly while switching
 // from and to private browsing mode.
 
-add_task(function test() {
+add_task(function* test() {
   const testPageURL = "http://mochi.test:8888/browser/" +
     "browser/components/privatebrowsing/test/browser/browser_privatebrowsing_windowtitle_page.html";
   requestLongerTimeout(2);
@@ -37,12 +37,12 @@ add_task(function test() {
     pb_about_pb_title = "Private Browsing - " + app_name + " (Private Browsing)";
   }
 
-  function* testTabTitle(aWindow, url, insidePB, expected_title) {
-    let tab = (yield BrowserTestUtils.openNewForegroundTab(aWindow.gBrowser));
-    yield BrowserTestUtils.loadURI(tab.linkedBrowser, url);
-    yield BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+  async function testTabTitle(aWindow, url, insidePB, expected_title) {
+    let tab = (await BrowserTestUtils.openNewForegroundTab(aWindow.gBrowser));
+    await BrowserTestUtils.loadURI(tab.linkedBrowser, url);
+    await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
 
-    yield BrowserTestUtils.waitForCondition(() => {
+    await BrowserTestUtils.waitForCondition(() => {
       return aWindow.document.title === expected_title;
     }, `Window title should be ${expected_title}, got ${aWindow.document.title}`);
 
@@ -51,9 +51,9 @@ add_task(function test() {
        " private browsing mode)");
 
     let win = aWindow.gBrowser.replaceTabWithWindow(tab);
-    yield BrowserTestUtils.waitForEvent(win, "load", false);
+    await BrowserTestUtils.waitForEvent(win, "load", false);
 
-    yield BrowserTestUtils.waitForCondition(() => {
+    await BrowserTestUtils.waitForCondition(() => {
       return win.document.title === expected_title;
     }, `Window title should be ${expected_title}, got ${aWindow.document.title}`);
 
@@ -61,17 +61,17 @@ add_task(function test() {
        " detached tab is correct (" + (insidePB ? "inside" : "outside") +
        " private browsing mode)");
 
-    yield Promise.all([ BrowserTestUtils.closeWindow(win),
+    await Promise.all([ BrowserTestUtils.closeWindow(win),
                         BrowserTestUtils.closeWindow(aWindow) ]);
   }
 
   function openWin(private) {
     return BrowserTestUtils.openNewBrowserWindow({ private });
   }
-  yield Task.spawn(testTabTitle((yield openWin(false)), "about:blank", false, page_without_title));
-  yield Task.spawn(testTabTitle((yield openWin(false)), testPageURL, false, page_with_title));
-  yield Task.spawn(testTabTitle((yield openWin(false)), "about:privatebrowsing", false, about_pb_title));
-  yield Task.spawn(testTabTitle((yield openWin(true)), "about:blank", true, pb_page_without_title));
-  yield Task.spawn(testTabTitle((yield openWin(true)), testPageURL, true, pb_page_with_title));
-  yield Task.spawn(testTabTitle((yield openWin(true)), "about:privatebrowsing", true, pb_about_pb_title));
+  yield testTabTitle((yield openWin(false)), "about:blank", false, page_without_title);
+  yield testTabTitle((yield openWin(false)), testPageURL, false, page_with_title);
+  yield testTabTitle((yield openWin(false)), "about:privatebrowsing", false, about_pb_title);
+  yield testTabTitle((yield openWin(true)), "about:blank", true, pb_page_without_title);
+  yield testTabTitle((yield openWin(true)), testPageURL, true, pb_page_with_title);
+  yield testTabTitle((yield openWin(true)), "about:privatebrowsing", true, pb_about_pb_title);
 });

browser/components/sessionstore/SessionMigration.jsm

@@ -66,11 +66,11 @@ var SessionMigrationInternal = {
    * Asynchronously read session restore state (JSON) from a path
    */
   readState: function(aPath) {
-    return Task.spawn(function() {
+    return Task.spawn(function*() {
       let bytes = yield OS.File.read(aPath);
       let text = gDecoder.decode(bytes);
       let state = JSON.parse(text);
-      throw new Task.Result(state);
+      return state;
     });
   },
   /**
@@ -87,7 +87,7 @@ var SessionMigration = {
    * Migrate a limited set of session data from one path to another.
    */
   migrate: function(aFromPath, aToPath) {
-    return Task.spawn(function() {
+    return Task.spawn(function*() {
       let inState = yield SessionMigrationInternal.readState(aFromPath);
       let outState = SessionMigrationInternal.convertState(inState);
       // Unfortunately, we can't use SessionStore's own SessionFile to

browser/components/sessionstore/test/browser_393716.js

@@ -8,7 +8,7 @@ const URL = "about:config";
 /**
  * Bug 393716 - Basic tests for getTabState(), setTabState(), and duplicateTab().
  */
-add_task(function test_set_tabstate() {
+add_task(function* test_set_tabstate() {
   let key = "Unique key: " + Date.now();
   let value = "Unique value: " + Math.random();
 
@@ -35,7 +35,7 @@ add_task(function test_set_tabstate() {
   gBrowser.removeTab(tab);
 });
 
-add_task(function test_set_tabstate_and_duplicate() {
+add_task(function* test_set_tabstate_and_duplicate() {
   let key2 = "key2";
   let value2 = "Value " + Math.random();
   let value3 = "Another value: " + Date.now();

browser/components/sessionstore/test/browser_456342.js

@@ -8,7 +8,7 @@ const URL = ROOT + "browser_456342_sample.xhtml";
 /**
  * Bug 456342 - Restore values from non-standard input field types.
  */
-add_task(function test_restore_nonstandard_input_values() {
+add_task(function* test_restore_nonstandard_input_values() {
   // Add tab with various non-standard input field types.
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_463205.js

@@ -10,7 +10,7 @@ const URL = ROOT + "browser_463205_sample.html";
  * website can't modify frame URLs and make us inject form data into the wrong
  * web pages.
  */
-add_task(function test_check_urls_before_restoring() {
+add_task(function* test_check_urls_before_restoring() {
   // Add a blank tab.
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_466937.js

@@ -8,7 +8,7 @@ const URL = ROOT + "browser_466937_sample.html";
 /**
  * Bug 466937 - Prevent file stealing with sessionstore.
  */
-add_task(function test_prevent_file_stealing() {
+add_task(function* test_prevent_file_stealing() {
   // Add a tab with some file input fields.
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_467409-backslashplosion.js

@@ -30,7 +30,7 @@ function createEntries(sessionData) {
   };
 }
 
-add_task(function test_nested_about_sessionrestore() {
+add_task(function* test_nested_about_sessionrestore() {
   // Prepare a blank tab.
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_485482.js

@@ -9,7 +9,7 @@ const URL = ROOT + "browser_485482_sample.html";
  * Bug 485482 - Make sure that we produce valid XPath expressions even for very
  * weird HTML documents.
  */
-add_task(function test_xpath_exp_for_strange_documents() {
+add_task(function* test_xpath_exp_for_strange_documents() {
   // Load a page with weird tag names.
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_528776.js

@@ -11,7 +11,7 @@ function browserWindowsCount(expected) {
      "number of open browser windows according to getBrowserState");
 }
 
-add_task(function() {
+add_task(function*() {
   browserWindowsCount(1);
 
   let win = yield BrowserTestUtils.openNewBrowserWindow();

browser/components/sessionstore/test/browser_broadcast.js

@@ -9,7 +9,7 @@ const INITIAL_VALUE = "browser_broadcast.js-initial-value-" + Date.now();
  * This test ensures we won't lose tab data queued in the content script when
  * closing a tab.
  */
-add_task(function flush_on_tabclose() {
+add_task(function* flush_on_tabclose() {
   let tab = yield createTabWithStorageData(["http://example.com"]);
   let browser = tab.linkedBrowser;
 
@@ -25,7 +25,7 @@ add_task(function flush_on_tabclose() {
  * This test ensures we won't lose tab data queued in the content script when
  * duplicating a tab.
  */
-add_task(function flush_on_duplicate() {
+add_task(function* flush_on_duplicate() {
   let tab = yield createTabWithStorageData(["http://example.com"]);
   let browser = tab.linkedBrowser;
 
@@ -45,7 +45,7 @@ add_task(function flush_on_duplicate() {
  * This test ensures we won't lose tab data queued in the content script when
  * a window is closed.
  */
-add_task(function flush_on_windowclose() {
+add_task(function* flush_on_windowclose() {
   let win = yield promiseNewWindow();
   let tab = yield createTabWithStorageData(["http://example.com"], win);
   let browser = tab.linkedBrowser;
@@ -62,7 +62,7 @@ add_task(function flush_on_windowclose() {
  * This test ensures that stale tab data is ignored when reusing a tab
  * (via e.g. setTabState) and does not overwrite the new data.
  */
-add_task(function flush_on_settabstate() {
+add_task(function* flush_on_settabstate() {
   let tab = yield createTabWithStorageData(["http://example.com"]);
   let browser = tab.linkedBrowser;
 
@@ -90,7 +90,7 @@ add_task(function flush_on_settabstate() {
  * asynchronously just before closing a tab. Flushing must re-send all data
  * that hasn't been received by chrome, yet.
  */
-add_task(function flush_on_tabclose_racy() {
+add_task(function* flush_on_tabclose_racy() {
   let tab = yield createTabWithStorageData(["http://example.com"]);
   let browser = tab.linkedBrowser;
 
@@ -115,17 +115,15 @@ function promiseNewWindow() {
   return deferred.promise;
 }
 
-function createTabWithStorageData(urls, win = window) {
-  return Task.spawn(function task() {
-    let tab = win.gBrowser.addTab();
-    let browser = tab.linkedBrowser;
+async function createTabWithStorageData(urls, win = window) {
+  let tab = win.gBrowser.addTab();
+  let browser = tab.linkedBrowser;
 
-    for (let url of urls) {
-      browser.loadURI(url);
-      yield promiseBrowserLoaded(browser);
-      yield modifySessionStorage(browser, {test: INITIAL_VALUE});
-    }
+  for (let url of urls) {
+    browser.loadURI(url);
+    await promiseBrowserLoaded(browser);
+    await modifySessionStorage(browser, {test: INITIAL_VALUE});
+  }
 
-    throw new Task.Result(tab);
-  });
+  return tab;
 }

browser/components/sessionstore/test/browser_capabilities.js

@@ -8,7 +8,7 @@
  * properties are (re)stored as disabled. Disallowed features must be
  * re-enabled when the tab is re-used by another tab restoration.
  */
-add_task(function docshell_capabilities() {
+add_task(function* docshell_capabilities() {
   let tab = yield createTab();
   let browser = tab.linkedBrowser;
   let docShell = browser.docShell;
@@ -69,8 +69,9 @@ add_task(function docshell_capabilities() {
   gBrowser.removeTab(tab);
 });
 
-function createTab() {
+async function createTab() {
   let tab = gBrowser.addTab("about:mozilla");
   let browser = tab.linkedBrowser;
-  return promiseBrowserLoaded(browser).then(() => tab);
+  await promiseBrowserLoaded(browser);
+  return tab;
 }

browser/components/sessionstore/test/browser_cookies.js

@@ -84,7 +84,7 @@ add_task(function* test_run() {
  * different cookie domains given in the Set-Cookie header. See above for some
  * usage examples.
  */
-var testCookieCollection = Task.async(function (params) {
+var testCookieCollection = async function (params) {
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;
 
@@ -102,14 +102,14 @@ var testCookieCollection = Task.async(function (params) {
   // Wait for the browser to load and the cookie to be set.
   // These two events can probably happen in no particular order,
   // so let's wait for them in parallel.
-  yield Promise.all([
+  await Promise.all([
     waitForNewCookie(),
     replaceCurrentURI(browser, uri)
   ]);
 
   // Check all URIs for which the cookie should be collected.
   for (let uri of params.cookieURIs || []) {
-    yield replaceCurrentURI(browser, uri);
+    await replaceCurrentURI(browser, uri);
 
     // Check the cookie.
     let cookie = getCookie();
@@ -121,7 +121,7 @@ var testCookieCollection = Task.async(function (params) {
 
   // Check all URIs for which the cookie should NOT be collected.
   for (let uri of params.noCookieURIs || []) {
-    yield replaceCurrentURI(browser, uri);
+    await replaceCurrentURI(browser, uri);
 
     // Cookie should be ignored.
     ok(!getCookie(), "no cookie collected");
@@ -130,22 +130,22 @@ var testCookieCollection = Task.async(function (params) {
   // Clean up.
   gBrowser.removeTab(tab);
   Services.cookies.removeAll();
-});
+};
 
 /**
  * Replace the current URI of the given browser by loading a new URI. The
  * browser's session history will be completely replaced. This function ensures
  * that the parent process has the lastest shistory data before resolving.
  */
-var replaceCurrentURI = Task.async(function* (browser, uri) {
+var replaceCurrentURI = async function(browser, uri) {
   // Replace the tab's current URI with the parent domain.
   let flags = Ci.nsIWebNavigation.LOAD_FLAGS_REPLACE_HISTORY;
   browser.loadURIWithFlags(uri, flags);
-  yield promiseBrowserLoaded(browser);
+  await promiseBrowserLoaded(browser);
 
   // Ensure the tab's session history is up-to-date.
-  yield TabStateFlusher.flush(browser);
-});
+  await TabStateFlusher.flush(browser);
+};
 
 /**
  * Waits for a new "*example.com" cookie to be added.

browser/components/sessionstore/test/browser_crashedTabs.js

@@ -125,7 +125,7 @@ function promiseTabCrashedReady(browser) {
  * Checks that if a tab crashes, that information about the tab crashed
  * page does not get added to the tab history.
  */
-add_task(function test_crash_page_not_in_history() {
+add_task(function* test_crash_page_not_in_history() {
   let newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;
   let browser = newTab.linkedBrowser;
@@ -154,7 +154,7 @@ add_task(function test_crash_page_not_in_history() {
  * to a non-blacklisted site (so the browser becomes remote again), that
  * we record history for that new visit.
  */
-add_task(function test_revived_history_from_remote() {
+add_task(function* test_revived_history_from_remote() {
   let newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;
   let browser = newTab.linkedBrowser;
@@ -193,7 +193,7 @@ add_task(function test_revived_history_from_remote() {
  * to a blacklisted site (so the browser stays non-remote), that
  * we record history for that new visit.
  */
-add_task(function test_revived_history_from_non_remote() {
+add_task(function* test_revived_history_from_non_remote() {
   let newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;
   let browser = newTab.linkedBrowser;
@@ -231,7 +231,7 @@ add_task(function test_revived_history_from_non_remote() {
  * Checks that we can revive a crashed tab back to the page that
  * it was on when it crashed.
  */
-add_task(function test_revive_tab_from_session_store() {
+add_task(function* test_revive_tab_from_session_store() {
   let newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;
   let browser = newTab.linkedBrowser;
@@ -284,7 +284,7 @@ add_task(function test_revive_tab_from_session_store() {
  * Checks that we can revive multiple crashed tabs back to the pages
  * that they were on when they crashed.
  */
-add_task(function test_revive_all_tabs_from_session_store() {
+add_task(function* test_revive_all_tabs_from_session_store() {
   let newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;
   let browser = newTab.linkedBrowser;
@@ -344,7 +344,7 @@ add_task(function test_revive_all_tabs_from_session_store() {
 /**
  * Checks that about:tabcrashed can close the current tab
  */
-add_task(function test_close_tab_after_crash() {
+add_task(function* test_close_tab_after_crash() {
   let newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;
   let browser = newTab.linkedBrowser;

browser/components/sessionstore/test/browser_dynamic_frames.js

@@ -7,7 +7,7 @@
  * Ensure that static frames of framesets are serialized but dynamically
  * inserted iframes are ignored.
  */
-add_task(function () {
+add_task(function*() {
   // This URL has the following frames:
   //  + data:text/html,A (static)
   //  + data:text/html,B (static)
@@ -45,7 +45,7 @@ add_task(function () {
  * dynamically inserted iframes are ignored. Navigating a subframe should
  * create a second root entry that doesn't contain any dynamic children either.
  */
-add_task(function () {
+add_task(function*() {
   // This URL has the following frames:
   //  + data:text/html,A (static)
   //  + data:text/html,C (dynamic iframe)

browser/components/sessionstore/test/browser_form_restore_events.js

@@ -9,7 +9,7 @@ const URL = ROOT + "browser_form_restore_events_sample.html";
  * Originally a test for Bug 476161, but then expanded to include all input
  * types in bug 640136.
  */
-add_task(function () {
+add_task(function*() {
   // Load a page with some form elements.
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_formdata.js

@@ -9,7 +9,7 @@ requestLongerTimeout(2);
  * This test ensures that form data collection respects the privacy level as
  * set by the user.
  */
-add_task(function test_formdata() {
+add_task(function* test_formdata() {
   const URL = "http://mochi.test:8888/browser/browser/components/" +
               "sessionstore/test/browser_formdata_sample.html";
 
@@ -18,23 +18,21 @@ add_task(function test_formdata() {
 
   // Creates a tab, loads a page with some form fields,
   // modifies their values and closes the tab.
-  function createAndRemoveTab() {
-    return Task.spawn(function () {
-      // Create a new tab.
-      let tab = gBrowser.addTab(URL);
-      let browser = tab.linkedBrowser;
-      yield promiseBrowserLoaded(browser);
+  function* createAndRemoveTab() {
+    // Create a new tab.
+    let tab = gBrowser.addTab(URL);
+    let browser = tab.linkedBrowser;
+    yield promiseBrowserLoaded(browser);
 
-      // Modify form data.
-      yield setInputValue(browser, {id: "txt", value: OUTER_VALUE});
-      yield setInputValue(browser, {id: "txt", value: INNER_VALUE, frame: 0});
+    // Modify form data.
+    yield setInputValue(browser, {id: "txt", value: OUTER_VALUE});
+    yield setInputValue(browser, {id: "txt", value: INNER_VALUE, frame: 0});
 
-      // Remove the tab.
-      yield promiseRemoveTab(tab);
-    });
+    // Remove the tab.
+    yield promiseRemoveTab(tab);
   }
 
-  yield createAndRemoveTab();
+  yield* createAndRemoveTab();
   let [{state: {formdata}}] = JSON.parse(ss.getClosedTabData(window));
   is(formdata.id.txt, OUTER_VALUE, "outer value is correct");
   is(formdata.children[0].id.txt, INNER_VALUE, "inner value is correct");
@@ -42,7 +40,7 @@ add_task(function test_formdata() {
   // Disable saving data for encrypted sites.
   Services.prefs.setIntPref("browser.sessionstore.privacy_level", 1);
 
-  yield createAndRemoveTab();
+  yield* createAndRemoveTab();
   [{state: {formdata}}] = JSON.parse(ss.getClosedTabData(window));
   is(formdata.id.txt, OUTER_VALUE, "outer value is correct");
   ok(!formdata.children, "inner value was *not* stored");
@@ -50,7 +48,7 @@ add_task(function test_formdata() {
   // Disable saving data for any site.
   Services.prefs.setIntPref("browser.sessionstore.privacy_level", 2);
 
-  yield createAndRemoveTab();
+  yield* createAndRemoveTab();
   [{state: {formdata}}] = JSON.parse(ss.getClosedTabData(window));
   ok(!formdata, "form data has *not* been stored");
 
@@ -63,7 +61,7 @@ add_task(function test_formdata() {
  * form data into a wrong website and that we always check the stored URL
  * before doing so.
  */
-add_task(function test_url_check() {
+add_task(function* test_url_check() {
   const URL = "data:text/html;charset=utf-8,<input%20id=input>";
   const VALUE = "value-" + Math.random();
 
@@ -98,7 +96,7 @@ add_task(function test_url_check() {
  * This test ensures that collecting form data works as expected when having
  * nested frame sets.
  */
-add_task(function test_nested() {
+add_task(function* test_nested() {
   const URL = "data:text/html;charset=utf-8," +
               "<iframe src='data:text/html;charset=utf-8," +
               "<input autofocus=true>'/>";
@@ -143,7 +141,7 @@ add_task(function test_nested() {
  * This test ensures that collecting form data for documents with
  * designMode=on works as expected.
  */
-add_task(function test_design_mode() {
+add_task(function* test_design_mode() {
   const URL = "data:text/html;charset=utf-8,<h1>mozilla</h1>" +
               "<script>document.designMode='on'</script>";
 

browser/components/sessionstore/test/browser_formdata_format.js

@@ -53,21 +53,16 @@ function test() {
     [ "value29", "value30" ],
     [ "", "value33" ]
   ];
-  let testTabCount = 0;
-  let callback = function() {
-    testTabCount--;
-    if (testTabCount == 0) {
-      finish();
-    }
-  };
 
+  let promises = [];
   for (let i = 0; i < formData.length; i++) {
-    testTabCount++;
-    testTabRestoreData(formData[i], expectedValues[i], callback);
+    promises.push(testTabRestoreData(formData[i], expectedValues[i]));
   }
+
+  Promise.all(promises).then(() => finish(), ex => ok(false, ex));
 }
 
-function testTabRestoreData(aFormData, aExpectedValue, aCallback) {
+async function testTabRestoreData(aFormData, aExpectedValue) {
   let URL = ROOT + "browser_formdata_format_sample.html";
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;
@@ -75,39 +70,35 @@ function testTabRestoreData(aFormData, aExpectedValue, aCallback) {
   aFormData.url = URL;
   let tabState = { entries: [{ url: URL }], formdata: aFormData };
 
-  Task.spawn(function () {
-    yield promiseBrowserLoaded(tab.linkedBrowser);
-    yield promiseTabState(tab, tabState);
+  await promiseBrowserLoaded(tab.linkedBrowser);
+  await promiseTabState(tab, tabState);
 
-    yield TabStateFlusher.flush(tab.linkedBrowser);
-    let restoredTabState = JSON.parse(ss.getTabState(tab));
-    let restoredFormData = restoredTabState.formdata;
+  await TabStateFlusher.flush(tab.linkedBrowser);
+  let restoredTabState = JSON.parse(ss.getTabState(tab));
+  let restoredFormData = restoredTabState.formdata;
 
-    if (restoredFormData) {
-      let doc = tab.linkedBrowser.contentDocument;
-      let input1 = doc.getElementById("input1");
-      let input2 = doc.querySelector("input[name=input2]");
+  if (restoredFormData) {
+    let doc = tab.linkedBrowser.contentDocument;
+    let input1 = doc.getElementById("input1");
+    let input2 = doc.querySelector("input[name=input2]");
 
-      // test format
-      ok("id" in restoredFormData || "xpath" in restoredFormData,
-        "FormData format is valid: " + restoredFormData);
-      // validate that there are no old keys
-      for (let key of Object.keys(restoredFormData)) {
-        if (["id", "xpath", "url"].indexOf(key) === -1) {
-          ok(false, "FormData format is invalid.");
-        }
+    // test format
+    ok("id" in restoredFormData || "xpath" in restoredFormData,
+       "FormData format is valid: " + restoredFormData);
+    // validate that there are no old keys
+    for (let key of Object.keys(restoredFormData)) {
+      if (["id", "xpath", "url"].indexOf(key) === -1) {
+        ok(false, "FormData format is invalid.");
       }
-      // test id
-      is(input1.value, aExpectedValue[0],
-        "FormData by 'id' has been restored correctly");
-      // test xpath
-      is(input2.value, aExpectedValue[1],
-        "FormData by 'xpath' has been restored correctly");
     }
+    // test id
+    is(input1.value, aExpectedValue[0],
+       "FormData by 'id' has been restored correctly");
+    // test xpath
+    is(input2.value, aExpectedValue[1],
+       "FormData by 'xpath' has been restored correctly");
+  }
 
-    // clean up
-    gBrowser.removeTab(tab);
-
-  // This test might time out if the task fails.
-  }).then(aCallback);
+  // clean up
+  gBrowser.removeTab(tab);
 }

browser/components/sessionstore/test/browser_formdata_xpath.js

@@ -38,7 +38,7 @@ const FIELDS = {
   "//input[@type='file'][2]":   [FILE1, FILE2]
 };
 
-add_task(function test_form_data_restoration() {
+add_task(function* test_form_data_restoration() {
   // Load page with some input fields.
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_frame_history.js

@@ -8,7 +8,7 @@
  */
 
 // Loading a toplevel frameset
-add_task(function() {
+add_task(function*() {
   let testURL = getRootDirectory(gTestPath) + "browser_frame_history_index.html";
   let tab = gBrowser.addTab(testURL);
   gBrowser.selectedTab = tab;
@@ -51,7 +51,7 @@ add_task(function() {
 });
 
 // Loading the frameset inside an iframe
-add_task(function() {
+add_task(function*() {
   let testURL = getRootDirectory(gTestPath) + "browser_frame_history_index2.html";
   let tab = gBrowser.addTab(testURL);
   gBrowser.selectedTab = tab;
@@ -98,7 +98,7 @@ add_task(function() {
 });
 
 // Now, test that we don't record history if the iframe is added dynamically
-add_task(function() {
+add_task(function*() {
   // Start with an empty history
     let blankState = JSON.stringify({
       windows: [{

browser/components/sessionstore/test/browser_frametree.js

@@ -13,7 +13,7 @@ const URL_FRAMESET = HTTPROOT + "browser_frametree_sample_frameset.html";
  * when a page starts loading and we also expect a valid frame tree to exist
  * when it has stopped loading.
  */
-add_task(function test_frametree() {
+add_task(function* test_frametree() {
   const FRAME_TREE_SINGLE = { href: URL };
   const FRAME_TREE_FRAMESET = {
     href: URL_FRAMESET,
@@ -65,7 +65,7 @@ add_task(function test_frametree() {
  * after the load event. SessionStore can't handle these and will not restore
  * or collect any data for them.
  */
-add_task(function test_frametree_dynamic() {
+add_task(function* test_frametree_dynamic() {
   // The frame tree as expected. The first two frames are static
   // and the third one was created on DOMContentLoaded.
   const FRAME_TREE = {

browser/components/sessionstore/test/browser_history_persist.js

@@ -7,7 +7,7 @@
  * Ensure that history entries that should not be persisted are restored in the
  * same state.
  */
-add_task(function check_history_not_persisted() {
+add_task(function* check_history_not_persisted() {
   // Create an about:blank tab
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;
@@ -44,7 +44,7 @@ add_task(function check_history_not_persisted() {
  * Check that entries default to being persisted when the attribute doesn't
  * exist
  */
-add_task(function check_history_default_persisted() {
+add_task(function* check_history_default_persisted() {
   // Create an about:blank tab
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_label_and_icon.js

@@ -20,7 +20,7 @@ add_task(function setup() {
 /**
  * Ensure that a pending tab has label and icon correctly set.
  */
-add_task(function test_label_and_icon() {
+add_task(function* test_label_and_icon() {
   // Create a new tab.
   let tab = gBrowser.addTab("about:robots");
   let browser = tab.linkedBrowser;

browser/components/sessionstore/test/browser_merge_closed_tabs.js

@@ -5,7 +5,7 @@
  * This test ensures that closed tabs are merged when restoring
  * a window state without overwriting tabs.
  */
-add_task(function () {
+add_task(function* () {
   const initialState = {
     windows: [{
       tabs: [

browser/components/sessionstore/test/browser_pageStyle.js

@@ -9,7 +9,7 @@ const URL_NESTED = getRootDirectory(gTestPath) + "browser_pageStyle_sample_neste
 /**
  * This test ensures that page style information is correctly persisted.
  */
-add_task(function page_style() {
+add_task(function* page_style() {
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;
   yield promiseBrowserLoaded(browser);
@@ -53,7 +53,7 @@ add_task(function page_style() {
  * This test ensures that page style notification from nested documents are
  * received and the page style is persisted correctly.
  */
-add_task(function nested_page_style() {
+add_task(function* nested_page_style() {
   let tab = gBrowser.addTab(URL_NESTED);
   let browser = tab.linkedBrowser;
   yield promiseBrowserLoaded(browser);

browser/components/sessionstore/test/browser_privatetabs.js

@@ -8,7 +8,7 @@ add_task(function cleanup() {
   }
 });
 
-add_task(function() {
+add_task(function*() {
   let URL_PUBLIC = "http://example.com/public/" + Math.random();
   let URL_PRIVATE = "http://example.com/private/" + Math.random();
   let tab1, tab2;
@@ -59,7 +59,7 @@ add_task(function() {
   }
 });
 
-add_task(function () {
+add_task(function* () {
   const FRAME_SCRIPT = "data:," +
     "docShell.QueryInterface%28Components.interfaces.nsILoadContext%29.usePrivateBrowsing%3Dtrue";
 
@@ -101,7 +101,7 @@ add_task(function () {
   is(ss.getClosedWindowCount(), 0, "no windows to restore");
 });
 
-add_task(function () {
+add_task(function* () {
   // Clear the list of closed windows.
   forgetClosedWindows();
 

browser/components/sessionstore/test/browser_restore_redirect.js

@@ -6,7 +6,7 @@ const TARGET = BASE + "restore_redirect_target.html";
 /**
  * Ensure that a http redirect leaves a working tab.
  */
-add_task(function check_http_redirect() {
+add_task(function* check_http_redirect() {
   let state = {
     entries: [{ url: BASE + "restore_redirect_http.html" }]
   };
@@ -32,7 +32,7 @@ add_task(function check_http_redirect() {
 /**
  * Ensure that a js redirect leaves a working tab.
  */
-add_task(function check_js_redirect() {
+add_task(function* check_js_redirect() {
   let state = {
     entries: [{ url: BASE + "restore_redirect_js.html" }]
   };

browser/components/sessionstore/test/browser_scrollPositions.js

@@ -22,7 +22,7 @@ requestLongerTimeout(2);
  * This test ensures that we properly serialize and restore scroll positions
  * for an average page without any frames.
  */
-add_task(function test_scroll() {
+add_task(function* test_scroll() {
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;
   yield promiseBrowserLoaded(browser);
@@ -65,7 +65,7 @@ add_task(function test_scroll() {
  * This tests ensures that we properly serialize and restore scroll positions
  * for multiple frames of pages with framesets.
  */
-add_task(function test_scroll_nested() {
+add_task(function* test_scroll_nested() {
   let tab = gBrowser.addTab(URL_FRAMESET);
   let browser = tab.linkedBrowser;
   yield promiseBrowserLoaded(browser);
@@ -109,7 +109,7 @@ add_task(function test_scroll_nested() {
  * Test that scroll positions persist after restoring background tabs in
  * a restored window (bug 1228518).
  */
-add_task(function test_scroll_background_tabs() {
+add_task(function* test_scroll_background_tabs() {
   pushPrefs(["browser.sessionstore.restore_on_demand", true]);
 
   let newWin = yield BrowserTestUtils.openNewBrowserWindow();

browser/components/sessionstore/test/browser_scrollPositionsReaderMode.js

@@ -17,7 +17,7 @@ requestLongerTimeout(2);
  * Test that scroll positions of about reader page after restoring background
  * tabs in a restored window (bug 1153393).
  */
-add_task(function test_scroll_background_about_reader_tabs() {
+add_task(function* test_scroll_background_about_reader_tabs() {
   pushPrefs(["browser.sessionstore.restore_on_demand", true]);
 
   let newWin = yield BrowserTestUtils.openNewBrowserWindow();

browser/components/sessionstore/test/browser_sessionHistory.js

@@ -8,7 +8,7 @@ requestLongerTimeout(2);
 /**
  * Ensure that starting a load invalidates shistory.
  */
-add_task(function test_load_start() {
+add_task(function* test_load_start() {
   // Create a new tab.
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;
@@ -36,7 +36,7 @@ add_task(function test_load_start() {
 /**
  * Ensure that anchor navigation invalidates shistory.
  */
-add_task(function test_hashchange() {
+add_task(function* test_hashchange() {
   const URL = "data:text/html;charset=utf-8,<a id=a href=%23>clickme</a>";
 
   // Create a new tab.
@@ -65,7 +65,7 @@ add_task(function test_hashchange() {
 /**
  * Ensure that loading pages from the bfcache invalidates shistory.
  */
-add_task(function test_pageshow() {
+add_task(function* test_pageshow() {
   const URL = "data:text/html;charset=utf-8,<h1>first</h1>";
   const URL2 = "data:text/html;charset=utf-8,<h1>second</h1>";
 
@@ -95,7 +95,7 @@ add_task(function test_pageshow() {
 /**
  * Ensure that subframe navigation invalidates shistory.
  */
-add_task(function test_subframes() {
+add_task(function* test_subframes() {
   const URL = "data:text/html;charset=utf-8," +
               "<iframe src=http%3A//example.com/ name=t></iframe>" +
               "<a id=a1 href=http%3A//example.com/1 target=t>clickme</a>" +
@@ -143,7 +143,7 @@ add_task(function test_subframes() {
 /**
  * Ensure that navigating from an about page invalidates shistory.
  */
-add_task(function test_about_page_navigate() {
+add_task(function* test_about_page_navigate() {
   // Create a new tab.
   let tab = gBrowser.addTab("about:blank");
   let browser = tab.linkedBrowser;
@@ -171,7 +171,7 @@ add_task(function test_about_page_navigate() {
 /**
  * Ensure that history.pushState and history.replaceState invalidate shistory.
  */
-add_task(function test_pushstate_replacestate() {
+add_task(function* test_pushstate_replacestate() {
   // Create a new tab.
   let tab = gBrowser.addTab("http://example.com/1");
   let browser = tab.linkedBrowser;
@@ -210,7 +210,7 @@ add_task(function test_pushstate_replacestate() {
 /**
  * Ensure that slow loading subframes will invalidate shistory.
  */
-add_task(function test_slow_subframe_load() {
+add_task(function* test_slow_subframe_load() {
   const SLOW_URL = "http://mochi.test:8888/browser/browser/components/" +
                    "sessionstore/test/browser_sessionHistory_slow.sjs";
 

browser/components/sessionstore/test/browser_sessionStorage.js

@@ -15,7 +15,7 @@ const INNER_VALUE = "inner-value-" + RAND;
  * This test ensures that setting, modifying and restoring sessionStorage data
  * works as expected.
  */
-add_task(function session_storage() {
+add_task(function* session_storage() {
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;
   yield promiseBrowserLoaded(browser);
@@ -102,7 +102,7 @@ add_task(function session_storage() {
  * This test ensures that purging domain data also purges data from the
  * sessionStorage data collected for tabs.
  */
-add_task(function purge_domain() {
+add_task(function* purge_domain() {
   let tab = gBrowser.addTab(URL);
   let browser = tab.linkedBrowser;
   yield promiseBrowserLoaded(browser);
@@ -126,7 +126,7 @@ add_task(function purge_domain() {
  * This test ensures that collecting sessionStorage data respects the privacy
  * levels as set by the user.
  */
-add_task(function respect_privacy_level() {
+add_task(function* respect_privacy_level() {
   let tab = gBrowser.addTab(URL + "&secure");
   yield promiseBrowserLoaded(tab.linkedBrowser);
   yield promiseRemoveTab(tab);