--- a/.eslintignore
+++ b/.eslintignore
@@ -68,17 +68,16 @@ browser/base/content/nsContextMenu.js
 browser/base/content/sanitizeDialog.js
 browser/base/content/test/**
 browser/base/content/newtab/**
 browser/components/customizableui/**
 browser/components/downloads/**
 browser/components/feeds/**
 browser/components/migration/**
 browser/components/*.js
-browser/components/places/**
 browser/components/pocket/**
 browser/components/preferences/**
 browser/components/privatebrowsing/**
 browser/components/sessionstore/**
 browser/components/shell/**
 browser/components/tabview/**
 browser/components/translation/**
 browser/components/uitour/**
@@ -157,17 +156,16 @@ toolkit/components/help/**
 toolkit/components/workerloader/tests/moduleF-syntax-error.js
 
 # Tests old non-star function generators
 toolkit/modules/tests/xpcshell/test_task.js
 
 # Not yet updated
 toolkit/components/osfile/**
 toolkit/components/passwordmgr/**
-toolkit/components/places/**
 
 # Uses preprocessing
 toolkit/content/contentAreaUtils.js
 toolkit/content/widgets/videocontrols.xml
 toolkit/components/jsdownloads/src/DownloadIntegration.jsm
 toolkit/components/search/nsSearchService.js
 toolkit/components/url-classifier/**
 toolkit/components/urlformatter/nsURLFormatter.js

--- a/browser/components/places/content/controller.js
+++ b/browser/components/places/content/controller.js
@@ -183,30 +183,33 @@ PlacesController.prototype = {
       return this._canInsert();
     case "placesCmd_new:bookmark":
       return this._canInsert();
     case "placesCmd_new:separator":
       return this._canInsert() &&
              !PlacesUtils.asQuery(this._view.result.root).queryOptions.excludeItems &&
              this._view.result.sortingMode ==
                  Ci.nsINavHistoryQueryOptions.SORT_BY_NONE;
-    case "placesCmd_show:info":
-      var selectedNode = this._view.selectedNode;
+    case "placesCmd_show:info": {
+      let selectedNode = this._view.selectedNode;
       return selectedNode && PlacesUtils.getConcreteItemId(selectedNode) != -1
-    case "placesCmd_reload":
+    }
+    case "placesCmd_reload": {
       // Livemark containers
-      var selectedNode = this._view.selectedNode;
+      let selectedNode = this._view.selectedNode;
       return selectedNode && this.hasCachedLivemarkInfo(selectedNode);
-    case "placesCmd_sortBy:name":
-      var selectedNode = this._view.selectedNode;
+    }
+    case "placesCmd_sortBy:name": {
+      let selectedNode = this._view.selectedNode;
       return selectedNode &&
              PlacesUtils.nodeIsFolder(selectedNode) &&
              !PlacesUIUtils.isContentsReadOnly(selectedNode) &&
              this._view.result.sortingMode ==
                  Ci.nsINavHistoryQueryOptions.SORT_BY_NONE;
+    }
     case "placesCmd_createBookmark":
       var node = this._view.selectedNode;
       return node && PlacesUtils.nodeIsURI(node) && node.itemId == -1;
     default:
       return false;
     }
   },
 
@@ -958,26 +961,23 @@ PlacesController.prototype = {
       else if (PlacesUtils.nodeIsQuery(node) &&
                PlacesUtils.asQuery(node).queryOptions.queryType ==
                  Ci.nsINavHistoryQueryOptions.QUERY_TYPE_HISTORY) {
         this._removeHistoryContainer(node);
       }
     }
 
     // Do removal in chunks to give some breath to main-thread.
-    function pagesChunkGenerator(aURIs) {
+    function* pagesChunkGenerator(aURIs) {
       while (aURIs.length) {
         let URIslice = aURIs.splice(0, REMOVE_PAGES_CHUNKLEN);
         PlacesUtils.bhistory.removePages(URIslice, URIslice.length);
-        Services.tm.mainThread.dispatch(function() {
-          try {
-            gen.next();
-          } catch (ex if ex instanceof StopIteration) {}
-        }, Ci.nsIThread.DISPATCH_NORMAL);
-        yield undefined;
+        Services.tm.mainThread.dispatch(() => gen.next(), 
+                                        Ci.nsIThread.DISPATCH_NORMAL);
+        yield unefined;
       }
     }
     let gen = pagesChunkGenerator(URIs);
     gen.next();
   },
 
   /**
    * Removes history visits for an history container node.

--- a/browser/components/places/content/editBookmarkOverlay.js
+++ b/browser/components/places/content/editBookmarkOverlay.js
@@ -361,31 +361,31 @@ var gEditItemOverlay = {
      * The value of the LAST_USED_ANNO annotation is the time (in the form of
      * Date.getTime) at which the folder has been last used.
      *
      * First we build the annotated folders array, each item has both the
      * folder identifier and the time at which it was last-used by this dialog
      * set. Then we sort it descendingly based on the time field.
      */
     this._recentFolders = [];
-    for (var i = 0; i < folderIds.length; i++) {
+    for (let i = 0; i < folderIds.length; i++) {
       var lastUsed = annos.getItemAnnotation(folderIds[i], LAST_USED_ANNO);
       this._recentFolders.push({ folderId: folderIds[i], lastUsed: lastUsed });
     }
     this._recentFolders.sort(function(a, b) {
       if (b.lastUsed < a.lastUsed)
         return -1;
       if (b.lastUsed > a.lastUsed)
         return 1;
       return 0;
     });
 
     var numberOfItems = Math.min(MAX_FOLDER_ITEM_IN_MENU_LIST,
                                  this._recentFolders.length);
-    for (var i = 0; i < numberOfItems; i++) {
+    for (let i = 0; i < numberOfItems; i++) {
       this._appendFolderItemToMenupopup(menupopup,
                                         this._recentFolders[i].folderId);
     }
 
     var defaultItem = this._getFolderMenuItem(aSelectedFolder);
     this._folderMenuList.selectedItem = defaultItem;
 
     // Set a selectedIndex attribute to show special icons

--- a/browser/components/places/content/places.js
+++ b/browser/components/places/content/places.js
@@ -413,17 +413,17 @@ var PlacesOrganizer = {
 
     let dateSvc = Cc["@mozilla.org/intl/scriptabledateformat;1"].
                   getService(Ci.nsIScriptableDateFormat);
 
     // Remove existing menu items.  Last item is the restoreFromFile item.
     while (restorePopup.childNodes.length > 1)
       restorePopup.removeChild(restorePopup.firstChild);
 
-    Task.spawn(function() {
+    Task.spawn(function* () {
       let backupFiles = yield PlacesBackups.getBackupFiles();
       if (backupFiles.length == 0)
         return;
 
       // Populate menu with backups.
       for (let i = 0; i < backupFiles.length; i++) {
         let fileSize = (yield OS.File.stat(backupFiles[i])).size;
         let [size, unit] = DownloadUtils.convertByteUnits(fileSize);
@@ -460,28 +460,26 @@ var PlacesOrganizer = {
       restorePopup.insertBefore(document.createElement("menuseparator"),
                                 document.getElementById("restoreFromFile"));
     });
   },
 
   /**
    * Called when a menuitem is selected from the restore menu.
    */
-  onRestoreMenuItemClick: function PO_onRestoreMenuItemClick(aMenuItem) {
-    Task.spawn(function() {
-      let backupName = aMenuItem.getAttribute("value");
-      let backupFilePaths = yield PlacesBackups.getBackupFiles();
-      for (let backupFilePath of backupFilePaths) {
-        if (OS.Path.basename(backupFilePath) == backupName) {
-          PlacesOrganizer.restoreBookmarksFromFile(backupFilePath);
-          break;
-        }
+  onRestoreMenuItemClick: Task.async(function* (aMenuItem) {
+    let backupName = aMenuItem.getAttribute("value");
+    let backupFilePaths = yield PlacesBackups.getBackupFiles();
+    for (let backupFilePath of backupFilePaths) {
+      if (OS.Path.basename(backupFilePath) == backupName) {
+        PlacesOrganizer.restoreBookmarksFromFile(backupFilePath);
+        break;
       }
-    });
-  },
+    }
+  }),
 
   /**
    * Called when 'Choose File...' is selected from the restore menu.
    * Prompts for a file and restores bookmarks to those in the file.
    */
   onRestoreBookmarksFromFile: function PO_onRestoreBookmarksFromFile() {
     let dirSvc = Cc["@mozilla.org/file/directory_service;1"].
                  getService(Ci.nsIProperties);
@@ -516,17 +514,17 @@ var PlacesOrganizer = {
     // confirm ok to delete existing bookmarks
     var prompts = Cc["@mozilla.org/embedcomp/prompt-service;1"].
                   getService(Ci.nsIPromptService);
     if (!prompts.confirm(null,
                          PlacesUIUtils.getString("bookmarksRestoreAlertTitle"),
                          PlacesUIUtils.getString("bookmarksRestoreAlert")))
       return;
 
-    Task.spawn(function() {
+    Task.spawn(function* () {
       try {
         yield BookmarkJSONUtils.importFromFile(aFilePath, true);
       } catch(ex) {
         PlacesOrganizer._showErrorAlert(PlacesUIUtils.getString("bookmarksRestoreParseError"));
       }
     });
   },
 
@@ -628,17 +626,17 @@ var PlacesOrganizer = {
       if ((focusedElement instanceof HTMLInputElement ||
            focusedElement instanceof HTMLTextAreaElement) &&
           /^editBMPanel.*/.test(focusedElement.parentNode.parentNode.id))
         focusedElement.blur();
 
       // don't update the panel if we are already editing this node unless we're
       // in multi-edit mode
       if (selectedNode) {
-        var concreteId = PlacesUtils.getConcreteItemId(selectedNode);
+        let concreteId = PlacesUtils.getConcreteItemId(selectedNode);
         var nodeIsSame = gEditItemOverlay.itemId == selectedNode.itemId ||
                          gEditItemOverlay.itemId == concreteId ||
                          (selectedNode.itemId == -1 && gEditItemOverlay.uri &&
                           gEditItemOverlay.uri == selectedNode.uri);
         if (nodeIsSame && detailsDeck.selectedIndex == 1 &&
             !gEditItemOverlay.multiEdit)
           return;
       }
@@ -648,17 +646,17 @@ var PlacesOrganizer = {
     gEditItemOverlay.uninitPanel(false);
 
     if (selectedNode && !PlacesUtils.nodeIsSeparator(selectedNode)) {
       detailsDeck.selectedIndex = 1;
       // Using the concrete itemId is arguably wrong.  The bookmarks API
       // does allow setting properties for folder shortcuts as well, but since
       // the UI does not distinct between the couple, we better just show
       // the concrete item properties for shortcuts to root nodes.
-      var concreteId = PlacesUtils.getConcreteItemId(selectedNode);
+      let concreteId = PlacesUtils.getConcreteItemId(selectedNode);
       var isRootItem = concreteId != -1 && PlacesUtils.isRootItem(concreteId);
       var readOnly = isRootItem ||
                      selectedNode.parent.itemId == PlacesUIUtils.leftPaneFolderId;
       var useConcreteId = isRootItem ||
                           PlacesUtils.nodeIsTagQuery(selectedNode);
       var itemId = -1;
       if (concreteId != -1 && useConcreteId)
         itemId = concreteId;
@@ -1201,23 +1199,23 @@ var ViewMenu = {
       result.sortingMode = Ci.nsINavHistoryQueryOptions.SORT_BY_NONE;
       return;
     }
 
     var columnId;
     if (aColumn) {
       columnId = aColumn.getAttribute("anonid");
       if (!aDirection) {
-        var sortColumn = this._getSortColumn();
+        let sortColumn = this._getSortColumn();
         if (sortColumn)
           aDirection = sortColumn.getAttribute("sortDirection");
       }
     }
     else {
-      var sortColumn = this._getSortColumn();
+      let sortColumn = this._getSortColumn();
       columnId = sortColumn ? sortColumn.getAttribute("anonid") : "title";
     }
 
     // This maps the possible values of columnId (i.e., anonid's of treecols in
     // placeContent) to the default sortingMode and sortingAnnotation values for
     // each column.
     //   key:  Sort key in the name of one of the
     //         nsINavHistoryQueryOptions.SORT_BY_* constants

--- a/browser/components/places/content/tree.xml
+++ b/browser/components/places/content/tree.xml
@@ -234,25 +234,25 @@
             while (parent && parent != root) {
               parents.push(parent);
               parent = parent.parent;
             }
 
             // Walk the list backwards (opening from the root of the hierarchy)
             // opening each folder as we go.
             for (var i = parents.length - 1; i >= 0; --i) {
-              var index = view.treeIndexForNode(parents[i]);
+              let index = view.treeIndexForNode(parents[i]);
               if (index != Ci.nsINavHistoryResultTreeViewer.INDEX_INVISIBLE &&
                   view.isContainer(index) && !view.isContainerOpen(index))
                 view.toggleOpenState(index);
             }
             // Select the specified node...
           }
 
-          var index = view.treeIndexForNode(node);
+          let index = view.treeIndexForNode(node);
           if (index == Ci.nsINavHistoryResultTreeViewer.INDEX_INVISIBLE)
             return;
 
           view.selection.select(index);
           // ... and ensure it's visible, not scrolled off somewhere.
           this.treeBoxObject.ensureRowIsVisible(index);
         ]]></body>
       </method>
@@ -654,20 +654,20 @@
 
           // For all the nodes we've found, highlight the corresponding
           // index in the tree.
           var resultview = this.view;
           var selection = this.view.selection;
           selection.selectEventsSuppressed = true;
           selection.clearSelection();
           // Open nodes containing found items
-          for (var i = 0; i < nodesToOpen.length; i++) {
+          for (let i = 0; i < nodesToOpen.length; i++) {
             nodesToOpen[i].containerOpen = true;
           }
-          for (var i = 0; i < nodes.length; i++) {
+          for (let i = 0; i < nodes.length; i++) {
             var index = resultview.treeIndexForNode(nodes[i]);
             if (index == Ci.nsINavHistoryResultTreeViewer.INDEX_INVISIBLE)
               continue;
             selection.rangedSelect(index, index, true);
           }
           selection.selectEventsSuppressed = false;
         ]]></body>
       </method>

--- a/browser/components/places/tests/browser/browser_435851_copy_query.js
+++ b/browser/components/places/tests/browser/browser_435851_copy_query.js
@@ -2,17 +2,17 @@
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
 /* test that copying a non movable query or folder shortcut makes a new query with the same url, not a deep copy */
 
 const SHORTCUT_URL = "place:folder=2";
 const QUERY_URL = "place:sort=8&maxResults=10";
 
-add_task(function copy_toolbar_shortcut() {
+add_task(function* copy_toolbar_shortcut() {
   let library = yield promiseLibrary();
 
   registerCleanupFunction(function () {
     library.close();
     PlacesUtils.bookmarks.removeFolderChildren(PlacesUtils.unfiledBookmarksFolderId);
   });
 
   library.PlacesOrganizer.selectLeftPaneQuery("BookmarksToolbar");
@@ -30,17 +30,17 @@ add_task(function copy_toolbar_shortcut(
 
   PlacesUtils.bookmarks.removeItem(toolbarCopyNode.itemId);
   library.PlacesOrganizer.selectLeftPaneQuery("BookmarksToolbar");
   is(library.PlacesOrganizer._places.selectedNode.type,
      Ci.nsINavHistoryResultNode.RESULT_TYPE_FOLDER_SHORTCUT,
      "original is still a folder shortcut");
 });
 
-add_task(function copy_history_query() {
+add_task(function* copy_history_query() {
   let library = yield promiseLibrary();
 
   library.PlacesOrganizer.selectLeftPaneQuery("History");
 
   yield promiseClipboard(function () { library.PlacesOrganizer._places.controller.copy(); },
                          PlacesUtils.TYPE_X_MOZ_PLACE);
 
   library.PlacesOrganizer.selectLeftPaneQuery("UnfiledBookmarks");

--- a/browser/components/places/tests/browser/browser_bookmarklet_windowOpen.js
+++ b/browser/components/places/tests/browser/browser_bookmarklet_windowOpen.js
@@ -8,17 +8,17 @@ function makeBookmarkFor(url, keyword) {
                                    title: "bookmarklet",
                                    url: url }),
     PlacesUtils.keywords.insert({url: url,
                                  keyword: keyword})
   ]);
 
 }
 
-add_task(function openKeywordBookmarkWithWindowOpen() {
+add_task(function* openKeywordBookmarkWithWindowOpen() {
   // This is the current default, but let's not assume that...
   yield new Promise((resolve, reject) => {
     SpecialPowers.pushPrefEnv({ 'set': [[ 'browser.link.open_newwindow', 3 ],
                                         [ 'dom.disable_open_during_load', true ]] },
                               resolve);
   });
 
   let moztab;

--- a/browser/components/places/tests/browser/browser_library_infoBox.js
+++ b/browser/components/places/tests/browser/browser_library_infoBox.js
@@ -92,17 +92,17 @@ gTests.push({
          "Correctly selected recently bookmarked node.");
       PO._places.selectNode(childNode);
       checkInfoBoxSelected(PO);
       ok(!infoBoxExpanderWrapper.hidden,
          "Expander button is not hidden for recently bookmarked node.");
       checkAddInfoFieldsNotCollapsed(PO);
 
       // open first bookmark
-      var view = ContentTree.view.view;
+      view = ContentTree.view.view;
       ok(view.rowCount > 0, "Bookmark item exists.");
       view.selection.select(0);
       checkInfoBoxSelected(PO);
       ok(!infoBoxExpanderWrapper.hidden,
          "Expander button is not hidden for bookmark item.");
       checkAddInfoFieldsNotCollapsed(PO);
       checkAddInfoFields(PO, "bookmark item");
 

--- a/browser/components/places/tests/browser/browser_toolbarbutton_menu_context.js
+++ b/browser/components/places/tests/browser/browser_toolbarbutton_menu_context.js
@@ -1,16 +1,16 @@
 var bookmarksMenuButton = document.getElementById("bookmarks-menu-button");
 var BMB_menuPopup = document.getElementById("BMB_bookmarksPopup");
 var BMB_showAllBookmarks = document.getElementById("BMB_bookmarksShowAll");
 var contextMenu = document.getElementById("placesContext");
 var newBookmarkItem = document.getElementById("placesContext_new:bookmark");
 
 waitForExplicitFinish();
-add_task(function testPopup() {
+add_task(function* testPopup() {
   info("Checking popup context menu before moving the bookmarks button");
   yield checkPopupContextMenu();
   let pos = CustomizableUI.getPlacementOfWidget("bookmarks-menu-button").position;
   CustomizableUI.addWidgetToArea("bookmarks-menu-button", CustomizableUI.AREA_PANEL);
   CustomizableUI.addWidgetToArea("bookmarks-menu-button", CustomizableUI.AREA_NAVBAR, pos);
   info("Checking popup context menu after moving the bookmarks button");
   yield checkPopupContextMenu();
 });

--- a/toolkit/components/places/BookmarkHTMLUtils.jsm
+++ b/toolkit/components/places/BookmarkHTMLUtils.jsm
@@ -1040,17 +1040,17 @@ BookmarkExporter.prototype = {
     this._writeLine("<!-- This is an automatically generated file.");
     this._writeLine("     It will be read and overwritten.");
     this._writeLine("     DO NOT EDIT! -->");
     this._writeLine('<META HTTP-EQUIV="Content-Type" CONTENT="text/html; ' +
                     'charset=UTF-8">');
     this._writeLine("<TITLE>Bookmarks</TITLE>");
   },
 
-  _writeContainer: function (aItem, aIndent = "") {
+  *_writeContainer(aItem, aIndent = "") {
     if (aItem == this._root) {
       this._writeLine("<H1>" + escapeHtmlEntities(this._root.title) + "</H1>");
       this._writeLine("");
     }
     else {
       this._write(aIndent + "<DT><H3");
       this._writeDateAttributes(aItem);
 
@@ -1067,28 +1067,29 @@ BookmarkExporter.prototype = {
     if (aItem.children)
       yield this._writeContainerContents(aItem, aIndent);
     if (aItem == this._root)
       this._writeLine(aIndent + "</DL>");
     else
       this._writeLine(aIndent + "</DL><p>");
   },
 
-  _writeContainerContents: function (aItem, aIndent) {
+  *_writeContainerContents(aItem, aIndent) {
     let localIndent = aIndent + EXPORT_INDENT;
 
     for (let child of aItem.children) {
-      if (child.annos && child.annos.some(anno => anno.name == PlacesUtils.LMANNO_FEEDURI))
-          this._writeLivemark(child, localIndent);
-      else if (child.type == PlacesUtils.TYPE_X_MOZ_PLACE_CONTAINER)
-          yield this._writeContainer(child, localIndent);
-      else if (child.type == PlacesUtils.TYPE_X_MOZ_PLACE_SEPARATOR)
+      if (child.annos && child.annos.some(anno => anno.name == PlacesUtils.LMANNO_FEEDURI)) {
+        this._writeLivemark(child, localIndent);
+      } else if (child.type == PlacesUtils.TYPE_X_MOZ_PLACE_CONTAINER) {
+        yield this._writeContainer(child, localIndent);
+      } else if (child.type == PlacesUtils.TYPE_X_MOZ_PLACE_SEPARATOR) {
         this._writeSeparator(child, localIndent);
-      else
+      } else {
         yield this._writeItem(child, localIndent);
+      }
     }
   },
 
   _writeSeparator: function (aItem, aIndent) {
     this._write(aIndent + "<HR");
     // We keep exporting separator titles, but don't support them anymore.
     if (aItem.title)
       this._writeAttribute("NAME", escapeHtmlEntities(aItem.title));
@@ -1101,17 +1102,17 @@ BookmarkExporter.prototype = {
     this._writeAttribute("FEEDURL", escapeUrl(feedSpec));
     let siteSpecAnno = aItem.annos.find(anno => anno.name == PlacesUtils.LMANNO_SITEURI);
     if (siteSpecAnno)
       this._writeAttribute("HREF", escapeUrl(siteSpecAnno.value));
     this._writeLine(">" + escapeHtmlEntities(aItem.title) + "</A>");
     this._writeDescription(aItem, aIndent);
   },
 
-  _writeItem: function (aItem, aIndent) {
+  *_writeItem(aItem, aIndent) {
     let uri = null;
     try {
       uri = NetUtil.newURI(aItem.uri);
     } catch (ex) {
       // If the item URI is invalid, skip the item instead of failing later.
       return;
     }
 
@@ -1140,17 +1141,17 @@ BookmarkExporter.prototype = {
     if (aItem.dateAdded)
       this._writeAttribute("ADD_DATE",
                            Math.floor(aItem.dateAdded / MICROSEC_PER_SEC));
     if (aItem.lastModified)
       this._writeAttribute("LAST_MODIFIED",
                            Math.floor(aItem.lastModified / MICROSEC_PER_SEC));
   },
 
-  _writeFaviconAttribute: function (aItem) {
+  *_writeFaviconAttribute(aItem) {
     if (!aItem.iconuri)
       return;
     let favicon;
     try {
       favicon  = yield PlacesUtils.promiseFaviconData(aItem.uri);
     } catch (ex) {
       Components.utils.reportError("Unexpected Error trying to fetch icon data");
       return;

--- a/toolkit/components/places/PlacesBackups.jsm
+++ b/toolkit/components/places/PlacesBackups.jsm
@@ -448,17 +448,20 @@ this.PlacesBackups = {
       try {
         let { count: nodeCount, hash: hash } =
           yield BookmarkJSONUtils.exportToFile(newBackupFile,
                                                { compress: true,
                                                  failIfHashIs: mostRecentHash });
         newFilenameWithMetaData = appendMetaDataToFilename(newBackupFilename,
                                                            { count: nodeCount,
                                                              hash: hash });
-      } catch (ex if ex.becauseSameHash) {
+      } catch (ex) {
+        if (!ex.becauseSameHash) {
+          throw ex;
+        }
         // The last backup already contained up-to-date information, just
         // rename it as if it was today's backup.
         this._backupFiles.shift();
         this._entries.shift();
         newBackupFile = mostRecentBackupFile;
         // Ensure we retain the proper extension when renaming
         // the most recent backup file.
         if (/\.json$/.test(OS.Path.basename(mostRecentBackupFile)))

--- a/toolkit/components/places/nsTaggingService.js
+++ b/toolkit/components/places/nsTaggingService.js
@@ -631,17 +631,17 @@ TagAutoCompleteSearch.prototype = {
       var newResult = new TagAutoCompleteResult(searchString,
         Ci.nsIAutoCompleteResult.RESULT_NOMATCH, 0, "", results, comments);
       listener.onSearchResult(self, newResult);
       return;
     }
     
     var self = this;
     // generator: if yields true, not done
-    function doSearch() {
+    function* doSearch() {
       var i = 0;
       while (i < searchResults.length) {
         if (self._stopped)
           yield false;
         // for each match, prepend what the user has typed so far
         if (searchResults[i].toLowerCase()
                             .indexOf(searchString.toLowerCase()) == 0 &&
             !comments.includes(searchResults[i])) {
@@ -677,18 +677,17 @@ TagAutoCompleteSearch.prototype = {
       var newResult = new TagAutoCompleteResult(searchString, searchResult, 0,
                                                 "", results, comments);
       listener.onSearchResult(self, newResult);
       yield false;
     }
     
     // chunk the search results via the generator
     var gen = doSearch();
-    while (gen.next());
-    gen.close();
+    while (gen.next().value);
   },
 
   /**
    * Stop an asynchronous search that is in progress
    */
   stopSearch: function PTACS_stopSearch() {
     this._stopped = true;
   },

--- a/toolkit/components/places/tests/autocomplete/head_autocomplete.js
+++ b/toolkit/components/places/tests/autocomplete/head_autocomplete.js
@@ -261,17 +261,17 @@ function run_test() {
 
   // By default assume we want to match tags
   appendTags = true;
 
   // Do an extra function if necessary
   if (func)
     func();
 
-  Task.spawn(function () {
+  Task.spawn(function* () {
     // Iterate over all tasks and execute them
     for (let [, [fn, args]] in Iterator(gNextTestSetupTasks)) {
       yield fn.apply(this, args);
     };
 
     // Clean up to allow tests to register more functions.
     gNextTestSetupTasks = [];
 
@@ -297,17 +297,17 @@ function do_removePages(aURIs)
 }
 
 // Utility function to mark pages as typed
 function markTyped(aURIs, aTitle)
 {
   gNextTestSetupTasks.push([task_markTyped, arguments]);
 }
 
-function task_markTyped(aURIs, aTitle)
+function* task_markTyped(aURIs, aTitle)
 {
   for (let uri of aURIs) {
     yield PlacesTestUtils.addVisits({
       uri: toURI(kURIs[uri]),
       transition: TRANSITION_TYPED,
       title: kTitles[aTitle]
     });
   }

--- a/toolkit/components/places/tests/browser/browser_bug248970.js
+++ b/toolkit/components/places/tests/browser/browser_bug248970.js
@@ -12,17 +12,17 @@ var visitedURIs = [
   "http://www.test-bookmark.com/",
   "http://www.test-redirect-permanent.com/",
   "http://www.test-redirect-temporary.com/",
   "http://www.test-embed.com/",
   "http://www.test-framed.com/",
   "http://www.test-download.com/"
 ].map(NetUtil.newURI.bind(NetUtil));
 
-add_task(function () {
+add_task(function* () {
   let windowsToClose = [];
   let placeItemsCount = 0;
 
   registerCleanupFunction(function() {
     windowsToClose.forEach(function(win) {
       win.close();
     });
   });

--- a/toolkit/components/places/tests/expiration/test_debug_expiration.js
+++ b/toolkit/components/places/tests/expiration/test_debug_expiration.js
@@ -67,17 +67,17 @@ add_task(function* test_expire_orphans_o
   do_check_eq(visits_in_database("http://page1.mozilla.org/"), 1);
   do_check_eq(visits_in_database("http://page2.mozilla.org/"), 1);
   do_check_false(page_in_database("http://page3.mozilla.org/"));
 
   // Clean up.
   yield PlacesTestUtils.clearHistory();
 });
 
-add_task(function test_expire_limited()
+add_task(function* test_expire_limited()
 {
   // Add visits to 2 pages and force a single expiration.
   // Only 1 page should survive.
   yield PlacesTestUtils.addVisits({
     uri: uri("http://page1.mozilla.org/"),
     visitDate: gNow++
   });
   yield PlacesTestUtils.addVisits({
@@ -91,17 +91,17 @@ add_task(function test_expire_limited()
   // Check that visits to the more recent page survived.
   do_check_false(page_in_database("http://page1.mozilla.org/"));
   do_check_eq(visits_in_database("http://page2.mozilla.org/"), 1);
 
   // Clean up.
   yield PlacesTestUtils.clearHistory();
 });
 
-add_task(function test_expire_unlimited()
+add_task(function* test_expire_unlimited()
 {
   // Add visits to 2 pages and force a single expiration.
   // Only 1 page should survive.
   yield PlacesTestUtils.addVisits({
     uri: uri("http://page1.mozilla.org/"),
     visitDate: gNow++
   });
   yield PlacesTestUtils.addVisits({

--- a/toolkit/components/places/tests/migration/test_current_from_v19.js
+++ b/toolkit/components/places/tests/migration/test_current_from_v19.js
@@ -29,14 +29,14 @@ add_task(function* initial_state() {
 add_task(function* database_is_valid() {
   Assert.equal(PlacesUtils.history.databaseStatus,
                PlacesUtils.history.DATABASE_STATUS_UPGRADED);
 
   let db = yield PlacesUtils.promiseDBConnection();
   Assert.equal((yield db.getSchemaVersion()), CURRENT_SCHEMA_VERSION);
 });
 
-add_task(function test_bookmark_guid_annotation_removed()
+add_task(function* test_bookmark_guid_annotation_removed()
 {
   let db = yield PlacesUtils.promiseDBConnection();
   Assert.equal((yield getTotalGuidAnnotationsCount(db)), 0,
                "There should be no more obsolete GUID annotations.");
 });

--- a/toolkit/components/places/tests/migration/test_current_from_v24.js
+++ b/toolkit/components/places/tests/migration/test_current_from_v24.js
@@ -8,17 +8,17 @@ add_task(function* setup() {
 add_task(function* database_is_valid() {
   Assert.equal(PlacesUtils.history.databaseStatus,
                PlacesUtils.history.DATABASE_STATUS_UPGRADED);
 
   let db = yield PlacesUtils.promiseDBConnection();
   Assert.equal((yield db.getSchemaVersion()), CURRENT_SCHEMA_VERSION);
 });
 
-add_task(function test_bookmark_guid_annotation_removed()
+add_task(function* test_bookmark_guid_annotation_removed()
 {
   yield PlacesUtils.bookmarks.eraseEverything();
 
   let db = yield PlacesUtils.promiseDBConnection();
   let m = new Map([
     [PlacesUtils.placesRootId, PlacesUtils.bookmarks.rootGuid],
     [PlacesUtils.bookmarksMenuFolderId, PlacesUtils.bookmarks.menuGuid],
     [PlacesUtils.toolbarFolderId, PlacesUtils.bookmarks.toolbarGuid],

--- a/toolkit/components/places/tests/queries/head_queries.js
+++ b/toolkit/components/places/tests/queries/head_queries.js
@@ -37,17 +37,17 @@ const olderthansixmonths = today - (DAY_
  * Generalized function to pull in an array of objects of data and push it into
  * the database.  It does NOT do any checking to see that the input is
  * appropriate.  This function is an asynchronous task, it can be called using
  * "Task.spawn" or using the "yield" function inside another task.
  */
 function* task_populateDB(aArray)
 {
   // Iterate over aArray and execute all instructions.
-  for ([, data] in Iterator(aArray)) {
+  for (let data of aArray) {
     try {
       // make the data object into a query data object in order to create proper
       // default values for anything left unspecified
       var qdata = new queryData(data);
       if (qdata.isVisit) {
         // Then we should add a visit for this node
         yield PlacesTestUtils.addVisits({
           uri: uri(qdata.uri),

--- a/toolkit/components/places/tests/queries/test_history_queries_titles_liveUpdate.js
+++ b/toolkit/components/places/tests/queries/test_history_queries_titles_liveUpdate.js
@@ -153,47 +153,51 @@ add_task(function* pages_searchterm_is_t
 {
   yield task_populateDB(gTestData);
 
   let [query, options] = newQueryWithOptions();
   query.searchTerms = "match";
   let root = PlacesUtils.history.executeQuery(query, options).root;
   root.containerOpen = true;
   compareArrayToResult([], root);
-  gTestData.forEach(function (data) {
+  for (let data of gTestData) {
     let uri = NetUtil.newURI(data.uri);
     let origTitle = data.title;
     data.title = "match";
-    yield PlacesTestUtils.addVisits({uri: uri, title: data.title});
+    yield PlacesTestUtils.addVisits({ uri: uri, title: data.title,
+                                      visitDate: data.lastVisit });
     compareArrayToResult([data], root);
     data.title = origTitle;
-    yield PlacesTestUtils.addVisits({uri: uri, title: data.title});
+    yield PlacesTestUtils.addVisits({ uri: uri, title: data.title,
+                                      visitDate: data.lastVisit });
     compareArrayToResult([], root);
-  });
+  }
 
   root.containerOpen = false;
   yield PlacesTestUtils.clearHistory();
 });
 
 add_task(function* visits_searchterm_is_title_query()
 {
   yield task_populateDB(gTestData);
 
   let [query, options] = newQueryWithOptions();
   query.searchTerms = "match";
   options.resultType = Ci.nsINavHistoryQueryOptions.RESULTS_AS_VISIT;
   let root = PlacesUtils.history.executeQuery(query, options).root;
   root.containerOpen = true;
   compareArrayToResult([], root);
-  gTestData.forEach(function (data) {
+  for (let data of gTestData) {
     let uri = NetUtil.newURI(data.uri);
     let origTitle = data.title;
     data.title = "match";
-    yield PlacesTestUtils.addVisits({uri: uri, title: data.title});
+    yield PlacesTestUtils.addVisits({ uri: uri, title: data.title,
+                                      visitDate: data.lastVisit });
     compareArrayToResult([data], root);
     data.title = origTitle;
-    yield PlacesTestUtils.addVisits({uri: uri, title: data.title});
+    yield PlacesTestUtils.addVisits({ uri: uri, title: data.title,
+                                      visitDate: data.lastVisit });
     compareArrayToResult([], root);
-  });
+  }
 
   root.containerOpen = false;
   yield PlacesTestUtils.clearHistory();
 });

--- a/toolkit/components/places/tests/queries/test_queryMultipleFolder.js
+++ b/toolkit/components/places/tests/queries/test_queryMultipleFolder.js
@@ -57,9 +57,9 @@ add_task(function* test_queryMultipleFol
   rootNode.containerOpen = true;
   resultLength = rootNode.childCount;
   Assert.equal(resultLength, maxResults);
   for (let i = 0; i < resultLength; ++i) {
     let node = rootNode.getChild(i);
     Assert.equal(bookmarkIds[i], node.itemId, node.uri);
   }
   rootNode.containerOpen = false;
-});
\ No newline at end of file
+});

--- a/toolkit/components/places/tests/queries/test_sort-date-site-grouping.js
+++ b/toolkit/components/places/tests/queries/test_sort-date-site-grouping.js
@@ -149,26 +149,26 @@ add_task(function* test_sort_date_site_g
 
   // We pass off to |checkFirstLevel| to check the first level of results.
   for (let index = 0; index < leveledTestData.length; index++) {
     let node = root.getChild(index);
     checkFirstLevel(index, node, roots);
   }
 
   // Test live updating.
-  testDataAddedLater.forEach(function(visit) {
+  for (let visit of testDataAddedLater) {
     yield task_populateDB([visit]);
     let oldLength = testData.length;
     let i = visit.levels[0];
     let j = visit.levels[1];
     testData.push(visit);
     leveledTestData[i][j].push(oldLength);
     compareArrayToResult(leveledTestData[i][j].
                          map(x => testData[x]), roots[i][j]);
-  });
+  }
 
   for (let i = 0; i < roots.length; i++) {
     for (let j = 0; j < roots[i].length; j++)
       roots[i][j].containerOpen = false;
   }
 
   root.containerOpen = false;
 });

--- a/toolkit/components/places/tests/queries/test_sorting.js
+++ b/toolkit/components/places/tests/queries/test_sorting.js
@@ -6,17 +6,17 @@
 
 var tests = [];
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_NONE,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 1: SORT BY NONE");
 
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://example.com/b",
         parentGuid: PlacesUtils.bookmarks.toolbarGuid,
         index: PlacesUtils.bookmarks.DEFAULT_INDEX,
         title: "y",
@@ -69,17 +69,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_TITLE_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 2: SORT BY TITLE");
 
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://example.com/b1",
         parentGuid: PlacesUtils.bookmarks.toolbarGuid,
         index: PlacesUtils.bookmarks.DEFAULT_INDEX,
         title: "y",
@@ -144,17 +144,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_DATE_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 3: SORT BY DATE");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isVisit: true,
         isDetails: true,
         isBookmark: true,
         parentGuid: PlacesUtils.bookmarks.toolbarGuid,
@@ -244,17 +244,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_URI_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 4: SORT BY URI");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isBookmark: true,
         isDetails: true,
         lastVisit: timeInMicroseconds,
         uri: "http://example.com/b",
@@ -350,17 +350,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_VISITCOUNT_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 5: SORT BY VISITCOUNT");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://example.com/a",
         lastVisit: timeInMicroseconds,
         title: "z",
@@ -451,17 +451,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_KEYWORD_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 6: SORT BY KEYWORD");
 
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://example.com/a",
         parentGuid: PlacesUtils.bookmarks.toolbarGuid,
         index: PlacesUtils.bookmarks.DEFAULT_INDEX,
         title: "z",
@@ -550,17 +550,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_DATEADDED_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 7: SORT BY DATEADDED");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://example.com/b1",
         parentGuid: PlacesUtils.bookmarks.toolbarGuid,
         index: 0,
@@ -640,17 +640,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_LASTMODIFIED_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 8: SORT BY LASTMODIFIED");
 
     var timeInMicroseconds = Date.now() * 1000;
     var timeAddedInMicroseconds = timeInMicroseconds - 10000;
 
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://example.com/b1",
@@ -738,17 +738,17 @@ tests.push({
   }
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_TAGS_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 9: SORT BY TAGS");
 
     this._unsortedData = [
       { isBookmark: true,
         uri: "http://url2.com/",
         parentGuid: PlacesUtils.bookmarks.toolbarGuid,
         index: PlacesUtils.bookmarks.DEFAULT_INDEX,
         title: "title x",
@@ -839,17 +839,17 @@ tests.push({
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 // SORT_BY_ANNOTATION_* (int32)
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_ANNOTATION_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 10: SORT BY ANNOTATION (int32)");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isVisit: true,
         isDetails: true,
         lastVisit: timeInMicroseconds,
         uri: "http://example.com/b1",
@@ -935,17 +935,17 @@ tests.push({
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 // SORT_BY_ANNOTATION_* (int64)
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_ANNOTATION_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 11: SORT BY ANNOTATION (int64)");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isVisit: true,
         isDetails: true,
         uri: "http://moz.com/",
         lastVisit: timeInMicroseconds,
@@ -1017,17 +1017,17 @@ tests.push({
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 // SORT_BY_ANNOTATION_* (string)
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_ANNOTATION_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 12: SORT BY ANNOTATION (string)");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isVisit: true,
         isDetails: true,
         uri: "http://moz.com/",
         lastVisit: timeInMicroseconds,
@@ -1099,17 +1099,17 @@ tests.push({
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 // SORT_BY_ANNOTATION_* (double)
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_ANNOTATION_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 13: SORT BY ANNOTATION (double)");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isVisit: true,
         isDetails: true,
         uri: "http://moz.com/",
         lastVisit: timeInMicroseconds,
@@ -1181,17 +1181,17 @@ tests.push({
 });
 
 ////////////////////////////////////////////////////////////////////////////////
 // SORT_BY_FRECENCY_*
 
 tests.push({
   _sortingMode: Ci.nsINavHistoryQueryOptions.SORT_BY_FRECENCY_ASCENDING,
 
-  setup: function() {
+  *setup() {
     do_print("Sorting test 13: SORT BY FRECENCY ");
 
     var timeInMicroseconds = Date.now() * 1000;
     this._unsortedData = [
       { isVisit: true,
         isDetails: true,
         uri: "http://moz.com/",
         lastVisit: timeInMicroseconds++,

--- a/toolkit/components/places/tests/unifiedcomplete/head_autocomplete.js
+++ b/toolkit/components/places/tests/unifiedcomplete/head_autocomplete.js
@@ -444,17 +444,17 @@ function* addTestEngine(basename, httpSe
 
     do_print("Adding engine from URL: " + dataUrl + basename);
     Services.search.addEngine(dataUrl + basename, null, null, false);
   });
 }
 
 // Ensure we have a default search engine and the keyword.enabled preference
 // set.
-add_task(function ensure_search_engine() {
+add_task(function* ensure_search_engine() {
   // keyword.enabled is necessary for the tests to see keyword searches.
   Services.prefs.setBoolPref("keyword.enabled", true);
 
   // Initialize the search service, but first set this geo IP pref to a dummy
   // string.  When the search service is initialized, it contacts the URI named
   // in this pref, which breaks the test since outside connections aren't
   // allowed.
   let geoPref = "browser.search.geoip.url";

--- a/toolkit/components/places/tests/unifiedcomplete/test_autoFill_default_behavior.js
+++ b/toolkit/components/places/tests/unifiedcomplete/test_autoFill_default_behavior.js
@@ -68,17 +68,17 @@ add_task(function* test_default_behavior
   Services.prefs.setBoolPref("browser.urlbar.autoFill.typed", false);
 
   // We are not restricting on typed, so we autoFill the bookmark even if we
   // are restricted to history.  We accept that cause not doing that
   // would be a perf hit and the privacy implications are very weak.
   do_print("Restrict history, bookmark, autoFill.typed = false, should autoFill");
   yield check_autocomplete({
     search: "bo",
-    matches: [ { uri: uri3, title: "bookmarked", style: [ "bookmark" ], style: [ "autofill", "heuristic" ],
+    matches: [ { uri: uri3, title: "bookmarked", style: [ "autofill", "heuristic" ],
                  icon: "chrome://global/skin/icons/error-16.png" } ],
     autofilled: "bookmarked/",
     completed: "bookmarked/"
   });
 
   do_print("Restrict history, common visit, autoFill.typed = false, should autoFill");
   yield check_autocomplete({
     search: "vi",

--- a/toolkit/components/places/tests/unit/test_420331_wyciwyg.js
+++ b/toolkit/components/places/tests/unit/test_420331_wyciwyg.js
@@ -12,12 +12,15 @@ function run_test()
 add_task(function* test_execute()
 {
   var testURI = uri("wyciwyg://nodontjudgeabookbyitscover");
 
   try
   {
     yield PlacesTestUtils.addVisits(testURI);
     do_throw("Should have generated an exception.");
-  } catch (ex if ex && ex.result == Cr.NS_ERROR_ILLEGAL_VALUE) {
+  } catch (ex) {
+    if (ex.result != Cr.NS_ERROR_ILLEGAL_VALUE) {
+      throw ex;
+    }
     // Adding wyciwyg URIs should raise NS_ERROR_ILLEGAL_VALUE.
   }
 });

--- a/toolkit/components/places/tests/unit/test_425563.js
+++ b/toolkit/components/places/tests/unit/test_425563.js
@@ -37,22 +37,22 @@ add_task(function* test_execute()
       transition: TRANSITION_REDIRECT_PERMANENT },
     { uri: uri("http://www.test-redirect-temporary.com/"),
       transition: TRANSITION_REDIRECT_TEMPORARY },
     { uri: uri("http://www.test-download.com/"),
       transition: TRANSITION_DOWNLOAD },
   ]);
 
   // check that all links are marked as visited
-  count_visited_URIs.forEach(function (visited_uri) {
+  for (let visited_uri of count_visited_URIs) {
     do_check_true(yield promiseIsURIVisited(uri(visited_uri)));
-  });
-  notcount_visited_URIs.forEach(function (visited_uri) {
+  }
+  for (let visited_uri of notcount_visited_URIs) {
     do_check_true(yield promiseIsURIVisited(uri(visited_uri)));
-  });
+  }
 
   // check that visit_count does not take in count embed and downloads
   // maxVisits query are directly binded to visit_count
   let options = PlacesUtils.history.getNewQueryOptions();
   options.sortingMode = options.SORT_BY_VISITCOUNT_DESCENDING;
   options.resultType = options.RESULTS_AS_VISIT;
   options.includeHidden = true;
   let query = PlacesUtils.history.getNewQuery();

--- a/toolkit/components/places/tests/unit/test_486978_sort_by_date_queries.js
+++ b/toolkit/components/places/tests/unit/test_486978_sort_by_date_queries.js
@@ -32,17 +32,18 @@ function run_test()
 }
 
 add_task(function* test_initialize()
 {
   var noon = new Date();
   noon.setHours(12);
 
   // Add visits.
-  for ([pageIndex, page] in Iterator(pages)) {
+  for (let pageIndex = 0; pageIndex < pages.length; ++pageIndex) {
+    let page = pages[pageIndex];
     yield PlacesTestUtils.addVisits({
       uri: uri(page),
       visitDate: noon - (pages.length - pageIndex) * 1000
     });
   }
 });
 
 /**

--- a/toolkit/components/places/tests/unit/test_async_history_api.js
+++ b/toolkit/components/places/tests/unit/test_async_history_api.js
@@ -366,17 +366,20 @@ add_task(function* test_non_addable_uri_
         uri: NetUtil.newURI(url),
         title: "test for " + url,
         visits: [
           new VisitInfo(),
         ],
       };
       places.push(place);
     }
-    catch (e if e.result === Cr.NS_ERROR_FAILURE) {
+    catch (e) {
+      if (e.result != Cr.NS_ERROR_FAILURE) {
+        throw e;
+      }
       // NetUtil.newURI() can throw if e.g. our app knows about imap://
       // but the account is not set up and so the URL is invalid for us.
       // Note this in the log but ignore as it's not the subject of this test.
       do_print("Could not construct URI for '" + url + "'; ignoring");
     }
   });
 
   let placesResult = yield promiseUpdatePlaces(places);
@@ -1075,17 +1078,20 @@ add_task(function* test_callbacks_not_su
         uri: NetUtil.newURI(url),
         title: "test for " + url,
         visits: [
           new VisitInfo(),
         ],
       };
       places.push(place);
     }
-    catch (e if e.result === Cr.NS_ERROR_FAILURE) {
+    catch (e) {
+      if (e.result != Cr.NS_ERROR_FAILURE) {
+        throw e;
+      }
       // NetUtil.newURI() can throw if e.g. our app knows about imap://
       // but the account is not set up and so the URL is invalid for us.
       // Note this in the log but ignore as it's not the subject of this test.
       do_print("Could not construct URI for '" + url + "'; ignoring");
     }
   });
 
   PlacesUtils.asyncHistory.updatePlaces(places, {});

--- a/toolkit/components/places/tests/unit/test_async_transactions.js
+++ b/toolkit/components/places/tests/unit/test_async_transactions.js
@@ -322,17 +322,17 @@ function* ensureBookmarksTreeRestoredCor
 
 function* ensureNonExistent(...aGuids) {
   for (let guid of aGuids) {
     Assert.strictEqual((yield PlacesUtils.promiseBookmarksTree(guid)), null);
   }
 }
 
 add_task(function* test_recycled_transactions() {
-  function ensureTransactThrowsFor(aTransaction) {
+  function* ensureTransactThrowsFor(aTransaction) {
     let [txns, undoPosition] = getTransactionsHistoryState();
     try {
       yield aTransaction.transact();
       do_throw("Shouldn't be able to use the same transaction twice");
     }
     catch(ex) { }
     ensureUndoState(txns, undoPosition);
   }

--- a/toolkit/components/places/tests/unit/test_bookmarks_html.js
+++ b/toolkit/components/places/tests/unit/test_bookmarks_html.js
@@ -298,17 +298,17 @@ function* testImportedBookmarks()
     root.containerOpen = false;
   }
 }
 
 function* checkItem(aExpected, aNode)
 {
   let id = aNode.itemId;
 
-  return Task.spawn(function() {
+  return Task.spawn(function* () {
     for (prop in aExpected) {
       switch (prop) {
         case "type":
           do_check_eq(aNode.type, aExpected.type);
           break;
         case "title":
           do_check_eq(aNode.title, aExpected.title);
           break;

--- a/toolkit/components/places/tests/unit/test_bookmarks_json.js
+++ b/toolkit/components/places/tests/unit/test_bookmarks_json.js
@@ -140,17 +140,17 @@ function* testImportedBookmarks() {
 
     root.containerOpen = false;
   }
 }
 
 function* checkItem(aExpected, aNode) {
   let id = aNode.itemId;
 
-  return Task.spawn(function() {
+  return Task.spawn(function* () {
     for (prop in aExpected) {
       switch (prop) {
         case "type":
           do_check_eq(aNode.type, aExpected.type);
           break;
         case "title":
           do_check_eq(aNode.title, aExpected.title);
           break;

--- a/toolkit/components/places/tests/unit/test_bookmarks_restore_notification.js
+++ b/toolkit/components/places/tests/unit/test_bookmarks_restore_notification.js
@@ -42,190 +42,176 @@ var uris = [
 //   run:        a method that actually runs the test
 var tests = [
   {
     desc:       "JSON restore: normal restore should succeed",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_SUCCESS,
     data:       NSIOBSERVER_DATA_JSON,
     folderId:   null,
-    run:        function () {
-      Task.spawn(function () {
-        this.file = yield promiseFile("bookmarks-test_restoreNotification.json");
-        addBookmarks();
+    run: Task.async(function* () {
+      this.file = yield promiseFile("bookmarks-test_restoreNotification.json");
+      addBookmarks();
 
-        yield BookmarkJSONUtils.exportToFile(this.file);
-        yield PlacesUtils.bookmarks.eraseEverything();
-        try {
-          yield BookmarkJSONUtils.importFromFile(this.file, true);
-        }
-        catch (e) {
-          do_throw("  Restore should not have failed");
-        }
-      }.bind(this));
-    }
+      yield BookmarkJSONUtils.exportToFile(this.file);
+      yield PlacesUtils.bookmarks.eraseEverything();
+      try {
+        yield BookmarkJSONUtils.importFromFile(this.file, true);
+      }
+      catch (e) {
+        do_throw("  Restore should not have failed");
+      }
+    })
   },
 
   {
     desc:       "JSON restore: empty file should succeed",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_SUCCESS,
     data:       NSIOBSERVER_DATA_JSON,
     folderId:   null,
-    run:        function () {
-      Task.spawn(function() {
-        this.file = yield promiseFile("bookmarks-test_restoreNotification.json");
-        try {
-          yield BookmarkJSONUtils.importFromFile(this.file, true);
-        }
-        catch (e) {
-          do_throw("  Restore should not have failed" + e);
-        }
-      }.bind(this));
-    }
+    run: Task.async(function* () {
+      this.file = yield promiseFile("bookmarks-test_restoreNotification.json");
+      try {
+        yield BookmarkJSONUtils.importFromFile(this.file, true);
+      }
+      catch (e) {
+        do_throw("  Restore should not have failed" + e);
+      }
+    })
   },
 
   {
     desc:       "JSON restore: nonexistent file should fail",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_FAILED,
     data:       NSIOBSERVER_DATA_JSON,
     folderId:   null,
-    run:        function () {
+    run: Task.async(function* () {
       this.file = Services.dirsvc.get("ProfD", Ci.nsILocalFile);
       this.file.append("this file doesn't exist because nobody created it 1");
-      Task.spawn(function() {
-        try {
-          yield BookmarkJSONUtils.importFromFile(this.file, true);
-          do_throw("  Restore should have failed");
-        }
-        catch (e) {
-        }
-      }.bind(this));
-    }
+      try {
+        yield BookmarkJSONUtils.importFromFile(this.file, true);
+        do_throw("  Restore should have failed");
+      }
+      catch (e) {
+      }
+    })
   },
 
   {
     desc:       "HTML restore: normal restore should succeed",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_SUCCESS,
     data:       NSIOBSERVER_DATA_HTML,
     folderId:   null,
-    run:        function () {
-      Task.spawn(function() {
-        this.file = yield promiseFile("bookmarks-test_restoreNotification.html");
-        addBookmarks();
-        yield BookmarkHTMLUtils.exportToFile(this.file);
-        yield PlacesUtils.bookmarks.eraseEverything();
-        try {
-          BookmarkHTMLUtils.importFromFile(this.file, false)
-                           .then(null, do_report_unexpected_exception);
-        }
-        catch (e) {
-          do_throw("  Restore should not have failed");
-        }
-      }.bind(this));
-    }
+    run: Task.async(function* () {
+      this.file = yield promiseFile("bookmarks-test_restoreNotification.html");
+      addBookmarks();
+      yield BookmarkHTMLUtils.exportToFile(this.file);
+      yield PlacesUtils.bookmarks.eraseEverything();
+      try {
+        BookmarkHTMLUtils.importFromFile(this.file, false)
+                         .then(null, do_report_unexpected_exception);
+      }
+      catch (e) {
+        do_throw("  Restore should not have failed");
+      }
+    })
   },
 
   {
     desc:       "HTML restore: empty file should succeed",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_SUCCESS,
     data:       NSIOBSERVER_DATA_HTML,
     folderId:   null,
-    run:        function () {
-      Task.spawn(function (){
-        this.file = yield promiseFile("bookmarks-test_restoreNotification.init.html");
-        try {
-          BookmarkHTMLUtils.importFromFile(this.file, false)
-                           .then(null, do_report_unexpected_exception);
-        }
-        catch (e) {
-          do_throw("  Restore should not have failed");
-        }
-      }.bind(this));
-    }
+    run: Task.async(function* () {
+      this.file = yield promiseFile("bookmarks-test_restoreNotification.init.html");
+      try {
+        BookmarkHTMLUtils.importFromFile(this.file, false)
+                         .then(null, do_report_unexpected_exception);
+      }
+      catch (e) {
+        do_throw("  Restore should not have failed");
+      }
+    })
   },
 
   {
     desc:       "HTML restore: nonexistent file should fail",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_FAILED,
     data:       NSIOBSERVER_DATA_HTML,
     folderId:   null,
-    run:        Task.async(function* () {
+    run: Task.async(function* () {
       this.file = Services.dirsvc.get("ProfD", Ci.nsILocalFile);
       this.file.append("this file doesn't exist because nobody created it 2");
       try {
         yield BookmarkHTMLUtils.importFromFile(this.file, false);
         do_throw("Should fail!");
       }
       catch (e) {}
-    }.bind(this))
+    })
   },
 
   {
     desc:       "HTML initial restore: normal restore should succeed",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_SUCCESS,
     data:       NSIOBSERVER_DATA_HTML_INIT,
     folderId:   null,
-    run:        function () {
-      Task.spawn(function () {
-        this.file = yield promiseFile("bookmarks-test_restoreNotification.init.html");
-        addBookmarks();
-        yield BookmarkHTMLUtils.exportToFile(this.file);
-        yield PlacesUtils.bookmarks.eraseEverything();
-        try {
-          BookmarkHTMLUtils.importFromFile(this.file, true)
-                           .then(null, do_report_unexpected_exception);
-        }
-        catch (e) {
-          do_throw("  Restore should not have failed");
-        }
-      }.bind(this));
-    }
+    run: Task.async(function* () {
+      this.file = yield promiseFile("bookmarks-test_restoreNotification.init.html");
+      addBookmarks();
+      yield BookmarkHTMLUtils.exportToFile(this.file);
+      yield PlacesUtils.bookmarks.eraseEverything();
+      try {
+        BookmarkHTMLUtils.importFromFile(this.file, true)
+                         .then(null, do_report_unexpected_exception);
+      }
+      catch (e) {
+        do_throw("  Restore should not have failed");
+      }
+    })
   },
 
   {
     desc:       "HTML initial restore: empty file should succeed",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_SUCCESS,
     data:       NSIOBSERVER_DATA_HTML_INIT,
     folderId:   null,
-    run:        function () {
-      Task.spawn(function () {
-        this.file = yield promiseFile("bookmarks-test_restoreNotification.init.html");
-        try {
-          BookmarkHTMLUtils.importFromFile(this.file, true)
-                           .then(null, do_report_unexpected_exception);
-        }
-        catch (e) {
-          do_throw("  Restore should not have failed");
-        }
-      }.bind(this));
-    }
+    run: Task.async(function* () {
+      this.file = yield promiseFile("bookmarks-test_restoreNotification.init.html");
+      try {
+        BookmarkHTMLUtils.importFromFile(this.file, true)
+                         .then(null, do_report_unexpected_exception);
+      }
+      catch (e) {
+        do_throw("  Restore should not have failed");
+      }
+    })
   },
 
   {
     desc:       "HTML initial restore: nonexistent file should fail",
     currTopic:  NSIOBSERVER_TOPIC_BEGIN,
     finalTopic: NSIOBSERVER_TOPIC_FAILED,
     data:       NSIOBSERVER_DATA_HTML_INIT,
     folderId:   null,
-    run:        Task.async(function* () {
+    run: Task.async(function* () {
       this.file = Services.dirsvc.get("ProfD", Ci.nsILocalFile);
       this.file.append("this file doesn't exist because nobody created it 3");
       try {
         yield BookmarkHTMLUtils.importFromFile(this.file, true);
         do_throw("Should fail!");
       }
       catch (e) {}
-    }.bind(this))
+    })
   }
 ];
 
 // nsIObserver that observes bookmarks-restore-begin.
 var beginObserver = {
   observe: function _beginObserver(aSubject, aTopic, aData) {
     var test = tests[currTestIndex];
 

--- a/toolkit/components/places/tests/unit/test_frecency.js
+++ b/toolkit/components/places/tests/unit/test_frecency.js
@@ -117,17 +117,17 @@ try {
   var tagssvc = Cc["@mozilla.org/browser/tagging-service;1"].
                 getService(Ci.nsITaggingService);
   var bmksvc = Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
                 getService(Ci.nsINavBookmarksService);
 } catch(ex) {
   do_throw("Could not get history service\n");
 } 
 
-function task_setCountDate(aURI, aCount, aDate)
+function* task_setCountDate(aURI, aCount, aDate)
 {
   // We need visits so that frecency can be computed over multiple visits
   let visits = [];
   for (let i = 0; i < aCount; i++) {
     visits.push({ uri: aURI, visitDate: aDate, transition: TRANSITION_TYPED });
   }
   yield PlacesTestUtils.addVisits(visits);
 }

--- a/toolkit/components/places/tests/unit/test_history_observer.js
+++ b/toolkit/components/places/tests/unit/test_history_observer.js
@@ -34,29 +34,25 @@ function onNotify(callback) {
   };
   PlacesUtils.history.addObserver(obs, false);
   return deferred.promise;
 }
 
 /**
  * Asynchronous task that adds a visit to the history database.
  */
-function task_add_visit(uri, timestamp, transition) {
+function* task_add_visit(uri, timestamp, transition) {
   uri = uri || NetUtil.newURI("http://firefox.com/");
   timestamp = timestamp || Date.now() * 1000;
   yield PlacesTestUtils.addVisits({
     uri: uri,
     transition: transition || TRANSITION_TYPED,
     visitDate: timestamp
   });
-  throw new Task.Result([uri, timestamp]);
-}
-
-function run_test() {
-  run_next_test();
+  return [uri, timestamp];
 }
 
 add_task(function* test_onVisit() {
   let promiseNotify = onNotify(function onVisit(aURI, aVisitID, aTime,
                                                 aSessionID, aReferringID,
                                                 aTransitionType, aGUID,
                                                 aHidden) {
     do_check_true(aURI.equals(testuri));

--- a/toolkit/components/places/tests/unit/test_hosts_triggers.js
+++ b/toolkit/components/places/tests/unit/test_hosts_triggers.js
@@ -145,17 +145,17 @@ add_task(function* test_moz_hosts_typed_
   yield PlacesTestUtils.addVisits(places);
 
   do_check_true(isHostInMozHosts(TEST_URI, true, null));
   yield PlacesTestUtils.clearHistory();
 });
 
 add_task(function* test_moz_hosts_www_remove()
 {
-  function test_removal(aURIToRemove, aURIToKeep, aCallback) {
+  function* test_removal(aURIToRemove, aURIToKeep, aCallback) {
     let places = [{ uri: aURIToRemove
                   , title: "test for " + aURIToRemove.spec
                   , transition: TRANSITION_TYPED
                   },
                   { uri: aURIToKeep
                   , title: "test for " + aURIToKeep.spec
                   , transition: TRANSITION_TYPED
                   }];

--- a/toolkit/components/places/tests/unit/test_isvisited.js
+++ b/toolkit/components/places/tests/unit/test_isvisited.js
@@ -60,15 +60,18 @@ add_task(function* test_execute()
       // but the account is not set up and so the URL is invalid for us.
       // Note this in the log but ignore as it's not the subject of this test.
       do_print("Could not construct URI for '" + currentURL + "'; ignoring");
     }
     if (cantAddUri) {
       try {
         yield PlacesTestUtils.addVisits({uri: cantAddUri, referrer: referrer});
         do_throw("Should have generated an exception.");
-      } catch(ex if ex && ex.result == Cr.NS_ERROR_ILLEGAL_VALUE) {
+      } catch(ex) {
+        if (ex.result != Cr.NS_ERROR_ILLEGAL_VALUE) {
+          throw ex;
+        }
       }
       do_check_false(yield promiseIsURIVisited(cantAddUri));
     }
   }
 });
 

--- a/toolkit/components/places/tests/unit/test_null_interfaces.js
+++ b/toolkit/components/places/tests/unit/test_null_interfaces.js
@@ -63,29 +63,29 @@ function run_test()
           func.apply(s, args);
   
           do_print(`The function did not throw! Is it one of the nothrow? ${nothrow}`);
           Assert.notEqual(nothrow.indexOf(n), -1);
 
           do_print("Must have been an expected nothrow, so no need to try again");
           tryAgain = false;
         }
-        catch(ex if ex.result == Cr.NS_ERROR_ILLEGAL_VALUE) {
-          do_print(`Caught an expected exception: ${ex.name}`);
-
-          do_print("Moving on to the next test..");
-          tryAgain = false;
-        }
-        catch(ex if ex.result == Cr.NS_ERROR_XPC_NEED_OUT_OBJECT) {
-          let pos = Number(ex.message.match(/object arg (\d+)/)[1]);
-          do_print(`Function call expects an out object at ${pos}`);
-          args[pos] = {};
-        }
-        catch(ex if ex.result == Cr.NS_ERROR_NOT_IMPLEMENTED) {
-          do_print(`Method not implemented exception: ${ex.name}`);
-
-          do_print("Moving on to the next test..");
-          tryAgain = false;
+        catch(ex) {
+          if (ex.result == Cr.NS_ERROR_ILLEGAL_VALUE) {
+            do_print(`Caught an expected exception: ${ex.name}`);
+            do_print("Moving on to the next test..");
+            tryAgain = false;
+          } else if (ex.result == Cr.NS_ERROR_XPC_NEED_OUT_OBJECT) {
+            let pos = Number(ex.message.match(/object arg (\d+)/)[1]);
+            do_print(`Function call expects an out object at ${pos}`);
+            args[pos] = {};
+          } else if (ex.result == Cr.NS_ERROR_NOT_IMPLEMENTED) {
+            do_print(`Method not implemented exception: ${ex.name}`);
+            do_print("Moving on to the next test..");
+            tryAgain = false;
+          } else {
+            throw ex;
+          }
         }
       }
     }
   }
 }

--- a/toolkit/components/places/tests/unit/test_preventive_maintenance.js
+++ b/toolkit/components/places/tests/unit/test_preventive_maintenance.js
@@ -1069,17 +1069,17 @@ tests.push({
 });
 
 //------------------------------------------------------------------------------
 
 tests.push({
   name: "L.2",
   desc: "Recalculate visit_count and last_visit_date",
 
-  setup: function() {
+  setup: function* () {
     function setVisitCount(aURL, aValue) {
       let stmt = mDBConn.createStatement(
         "UPDATE moz_places SET visit_count = :count WHERE url = :url"
       );
       stmt.params.count = aValue;
       stmt.params.url = aURL;
       stmt.execute();
       stmt.finalize();
@@ -1262,17 +1262,17 @@ tests.push({
 //------------------------------------------------------------------------------
 
 // main
 function run_test()
 {
   run_next_test();
 }
 
-add_task(function test_preventive_maintenance()
+add_task(function* test_preventive_maintenance()
 {
   // Force initialization of the bookmarks hash. This test could cause
   // it to go out of sync due to direct queries on the database.
   yield PlacesTestUtils.addVisits(uri("http://force.bookmarks.hash"));
   do_check_false(bs.isBookmarked(uri("http://force.bookmarks.hash")));
 
   // Get current bookmarks max ID for cleanup
   let stmt = mDBConn.createStatement("SELECT MAX(id) FROM moz_bookmarks");

--- a/toolkit/components/places/tests/unit/test_promiseBookmarksTree.js
+++ b/toolkit/components/places/tests/unit/test_promiseBookmarksTree.js
@@ -206,27 +206,27 @@ function* test_promiseBookmarksTreeAgain
     yield PlacesUtils.promiseItemId(aItemGuid) : PlacesUtils.placesRootId;
   let node = PlacesUtils.getFolderContents(itemId).root;
   return yield test_promiseBookmarksTreeForEachNode(node, aOptions, aExcludedGuids);
 }
 
 add_task(function* () {
   // Add some bookmarks to cover various use cases.
   yield new_bookmark({ parentGuid: PlacesUtils.bookmarks.toolbarGuid });
-  yield new_folder({ parentGuid: PlacesUtils.bookmarks.menuGuid
-                   , annotations: [{ name: "TestAnnoA", value: "TestVal"
-                                   , name: "TestAnnoB", value: 0 }]});
+  yield new_folder({ parentGuid: PlacesUtils.bookmarks.menuGuid,
+                     annotations: [{ name: "TestAnnoA", value: "TestVal" },
+                                   { name: "TestAnnoB", value: 0 }]});
   let sepInfo = { parentGuid: PlacesUtils.bookmarks.menuGuid };
   yield PlacesTransactions.NewSeparator(sepInfo).transact();
   let folderGuid = yield new_folder({ parentGuid: PlacesUtils.bookmarks.menuGuid });
-  yield new_bookmark({ title: null
-                     , parentGuid: folderGuid
-                     , keyword: "test_keyword"
-                     , tags: ["TestTagA", "TestTagB"]
-                     , annotations: [{ name: "TestAnnoA", value: "TestVal2"}]});
+  yield new_bookmark({ title: null,
+                       parentGuid: folderGuid,
+                       keyword: "test_keyword",
+                       tags: ["TestTagA", "TestTagB"],
+                       annotations: [{ name: "TestAnnoA", value: "TestVal2"}]});
   let urlWithCharsetAndFavicon = uri("http://charset.and.favicon");
   yield new_bookmark({ parentGuid: folderGuid, url: urlWithCharsetAndFavicon });
   yield PlacesUtils.setCharsetForURI(urlWithCharsetAndFavicon, "UTF-8");
   yield promiseSetIconForPage(urlWithCharsetAndFavicon, SMALLPNG_DATA_URI);
   // Test the default places root without specifying it.
   yield test_promiseBookmarksTreeAgainstResult();
 
   // Do specify it

--- a/toolkit/components/places/tests/unit/test_removeVisitsByTimeframe.js
+++ b/toolkit/components/places/tests/unit/test_removeVisitsByTimeframe.js
@@ -10,17 +10,17 @@ const PLACE_URI = uri("place:queryType=0
 
 function* cleanup() {
   yield PlacesTestUtils.clearHistory();
   yield PlacesUtils.bookmarks.eraseEverything();
   // This is needed to remove place: entries.
   DBConn().executeSimpleSQL("DELETE FROM moz_places");
 }
 
-add_task(function remove_visits_outside_unbookmarked_uri() {
+add_task(function* remove_visits_outside_unbookmarked_uri() {
   do_print("*** TEST: Remove some visits outside valid timeframe from an unbookmarked URI");
  
   do_print("Add 10 visits for the URI from way in the past.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: TEST_URI, visitDate: NOW - 1000 - i });
   }
   yield PlacesTestUtils.addVisits(visits);
@@ -51,17 +51,17 @@ add_task(function remove_visits_outside_
 
   yield PlacesTestUtils.promiseAsyncUpdates();
   do_print("Frecency should be positive.")
   do_check_true(frecencyForUrl(TEST_URI) > 0);
 
   yield cleanup();
 });
 
-add_task(function remove_visits_outside_bookmarked_uri() {
+add_task(function* remove_visits_outside_bookmarked_uri() {
   do_print("*** TEST: Remove some visits outside valid timeframe from a bookmarked URI");
 
   do_print("Add 10 visits for the URI from way in the past.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: TEST_URI, visitDate: NOW - 1000 - i });
   }
   yield PlacesTestUtils.addVisits(visits);
@@ -98,17 +98,17 @@ add_task(function remove_visits_outside_
   yield PlacesTestUtils.promiseAsyncUpdates();
 
   do_print("Frecency should be positive.")
   do_check_true(frecencyForUrl(TEST_URI) > 0);
 
   yield cleanup();
 });
 
-add_task(function remove_visits_unbookmarked_uri() {
+add_task(function* remove_visits_unbookmarked_uri() {
   do_print("*** TEST: Remove some visits from an unbookmarked URI");
 
   do_print("Add 10 visits for the URI from now to 9 usecs in the past.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: TEST_URI, visitDate: NOW - i });
   }
   yield PlacesTestUtils.addVisits(visits);
@@ -139,17 +139,17 @@ add_task(function remove_visits_unbookma
   yield PlacesTestUtils.promiseAsyncUpdates();
 
   do_print("Frecency should be positive.")
   do_check_true(frecencyForUrl(TEST_URI) > 0);
 
   yield cleanup();
 });
 
-add_task(function remove_visits_bookmarked_uri() {
+add_task(function* remove_visits_bookmarked_uri() {
   do_print("*** TEST: Remove some visits from a bookmarked URI");
 
   do_print("Add 10 visits for the URI from now to 9 usecs in the past.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: TEST_URI, visitDate: NOW - i });
   }
   yield PlacesTestUtils.addVisits(visits);
@@ -186,17 +186,17 @@ add_task(function remove_visits_bookmark
   yield PlacesTestUtils.promiseAsyncUpdates()
 
   do_print("Frecency should be positive.")
   do_check_true(frecencyForUrl(TEST_URI) > 0);
 
   yield cleanup();
 });
 
-add_task(function remove_all_visits_unbookmarked_uri() {
+add_task(function* remove_all_visits_unbookmarked_uri() {
   do_print("*** TEST: Remove all visits from an unbookmarked URI");
 
   do_print("Add some visits for the URI.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: TEST_URI, visitDate: NOW - i });
   }
   yield PlacesTestUtils.addVisits(visits);
@@ -219,17 +219,17 @@ add_task(function remove_all_visits_unbo
   root.containerOpen = false;
 
   do_print("asyncHistory.isURIVisited should return false.");
   do_check_false(yield promiseIsURIVisited(TEST_URI));
 
   yield cleanup();
 });
 
-add_task(function remove_all_visits_unbookmarked_place_uri() {
+add_task(function* remove_all_visits_unbookmarked_place_uri() {
   do_print("*** TEST: Remove all visits from an unbookmarked place: URI");
   do_print("Add some visits for the URI.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: PLACE_URI, visitDate: NOW - i });
   }
   yield PlacesTestUtils.addVisits(visits);
 
@@ -255,17 +255,17 @@ add_task(function remove_all_visits_unbo
   yield PlacesTestUtils.promiseAsyncUpdates();
 
   do_print("Frecency should be zero.")
   do_check_eq(frecencyForUrl(PLACE_URI.spec), 0);
 
   yield cleanup();
 });
 
-add_task(function remove_all_visits_bookmarked_uri() {
+add_task(function* remove_all_visits_bookmarked_uri() {
   do_print("*** TEST: Remove all visits from a bookmarked URI");
 
   do_print("Add some visits for the URI.");
   let visits = [];
   for (let i = 0; i < 10; i++) {
     visits.push({ uri: TEST_URI, visitDate: NOW - i });
   }
   yield PlacesTestUtils.addVisits(visits);
@@ -301,17 +301,17 @@ add_task(function remove_all_visits_book
   yield PlacesTestUtils.promiseAsyncUpdates();
 
   do_print("Frecency should be negative.")
   do_check_true(frecencyForUrl(TEST_URI) < 0);
 
   yield cleanup();
 });
 
-add_task(function remove_all_visits_bookmarked_uri() {
+add_task(function* remove_all_visits_bookmarked_uri() {
   do_print("*** TEST: Remove some visits from a zero frecency URI retains zero frecency");
 
   do_print("Add some visits for the URI.");
   yield PlacesTestUtils.addVisits([
     { uri: TEST_URI, transition: TRANSITION_FRAMED_LINK, visitDate: (NOW - 86400000000) },
     { uri: TEST_URI, transition: TRANSITION_FRAMED_LINK, visitDate: NOW }
   ]);
 
@@ -321,12 +321,8 @@ add_task(function remove_all_visits_book
 
   do_print("URI should still exist in moz_places.");
   do_check_true(page_in_database(TEST_URI.spec));
   do_print("Frecency should be zero.")
   do_check_eq(frecencyForUrl(TEST_URI), 0);
 
   yield cleanup();
 });
-
-function run_test() {
-  run_next_test();
-}