--- a/browser/.eslintrc.js
+++ b/browser/.eslintrc.js
@@ -1,16 +1,11 @@
 "use strict";
 
 module.exports = {
   "extends": [
     "../toolkit/.eslintrc.js"
   ],
 
   "rules": {
-    "no-unused-vars": ["error", {
-      "vars": "local",
-      "varsIgnorePattern": "^Cc|Ci|Cu|Cr|EXPORTED_SYMBOLS",
-      "args": "none",
-    }],
     "no-shadow": "error"
   }
 };

--- a/browser/base/.eslintrc.js
+++ b/browser/base/.eslintrc.js
@@ -1,11 +1,4 @@
 "use strict";
 
 module.exports = {
-  "rules": {
-    "no-unused-vars": ["error", {
-      "vars": "local",
-      "varsIgnorePattern": "^Cc|Ci|Cu|Cr|EXPORTED_SYMBOLS",
-      "args": "none",
-    }]
-  }
 };

--- a/storage/test/unit/test_bug-429521.js
+++ b/storage/test/unit/test_bug-429521.js
@@ -19,17 +19,17 @@ function test_bug429521() {
   print("*** test_bug429521: started");
 
   try {
     while (stmt.executeStep()) {
       print("*** test_bug429521: step() Read wrapper.row.zone");
 
       // BUG: the print commands after the following statement
       // are never executed. Script stops immediately.
-      var tzId = stmt.row.zone;
+      stmt.row.zone;
 
       print("*** test_bug429521: step() Read wrapper.row.zone finished");
     }
   } catch (e) {
     print("*** test_bug429521: " + e);
   }
 
   print("*** test_bug429521: finished");

--- a/storage/test/unit/test_statement_executeAsync.js
+++ b/storage/test/unit/test_statement_executeAsync.js
@@ -823,17 +823,17 @@ function test_not_right_owning_statement
     "VALUES (:int)"
   );
   let stmt2 = makeTestStatement(
     "INSERT INTO test (id) " +
     "VALUES (:int)"
   );
 
   let array1 = stmt1.newBindingParamsArray();
-  let array2 = stmt2.newBindingParamsArray();
+  stmt2.newBindingParamsArray();
   let bp = array1.newBindingParams();
   bp.bindByName("int", INTEGER);
   array1.addParams(bp);
 
   // We should not be able to bind array1 since it was created from stmt1.
   expectError(Cr.NS_ERROR_UNEXPECTED,
               () => stmt2.bindParameters(array1));
 

--- a/storage/test/unit/test_storage_connection.js
+++ b/storage/test/unit/test_storage_connection.js
@@ -176,17 +176,17 @@ add_task(function* test_createTable() {
   } finally {
     if (con) {
       con.close();
     }
   }
 });
 
 add_task(function* test_defaultSynchronousAtNormal() {
-  var msc = getOpenedDatabase();
+  getOpenedDatabase();
   var stmt = createStatement("PRAGMA synchronous;");
   try {
     stmt.executeStep();
     do_check_eq(1, stmt.getInt32(0));
   }
   finally {
     stmt.reset();
     stmt.finalize();

--- a/toolkit/.eslintrc.js
+++ b/toolkit/.eslintrc.js
@@ -149,21 +149,21 @@ module.exports = {
 
     // Error on newline where a semicolon is needed
     "no-unexpected-multiline": "error",
 
     // No unreachable statements
     "no-unreachable": "error",
 
     // No declaring variables that are never used
-    // "no-unused-vars": ["error", {
-    //   "vars": "local",
-    //   "varsIgnorePattern": "^Cc|Ci|Cu|Cr|EXPORTED_SYMBOLS",
-    //   "args": "none",
-    // }],
+    "no-unused-vars": ["error", {
+      "vars": "local",
+      "varsIgnorePattern": "^Cc|Ci|Cu|Cr|EXPORTED_SYMBOLS",
+      "args": "none",
+    }],
 
     // No using variables before defined
     // "no-use-before-define": ["error", "nofunc"],
 
     // No using with
     "no-with": "error",
 
     // No spacing inside rest or spread expressions

--- a/toolkit/components/.eslintrc.js
+++ b/toolkit/components/.eslintrc.js
@@ -1,11 +1,6 @@
 "use strict";
 
 module.exports = {
   "rules": {
-    "no-unused-vars": ["error", {
-      "vars": "local",
-      "varsIgnorePattern": "^Cc|Ci|Cu|Cr|EXPORTED_SYMBOLS",
-      "args": "none",
-    }]
   }
 };

--- a/toolkit/content/aboutSupport.js
+++ b/toolkit/content/aboutSupport.js
@@ -432,17 +432,17 @@ var snapshotFormatters = {
       }
       addRow(id, "gpuActive", strings.GetStringFromName(active));
       addRows(id, trs);
     }
     showGpu("gpu-1", "");
     showGpu("gpu-2", "2");
 
     // Remove adapter keys.
-    for (let [prop, key] of adapterKeys) {
+    for (let [prop, /* key */] of adapterKeys) {
       delete data[prop];
       delete data[prop + "2"];
     }
     delete data.isGPU2Active;
 
     let featureLog = data.featureLog;
     delete data.featureLog;
 

--- a/toolkit/content/aboutTelemetry.js
+++ b/toolkit/content/aboutTelemetry.js
@@ -409,17 +409,16 @@ var PingPicker = {
     // Update the displayed ping.
     yield this._updateArchivedPingData();
   }),
 
   _renderWeeks: function() {
     let weekSelector = document.getElementById("choose-ping-week");
     removeAllChildNodes(weekSelector);
 
-    let index = 0;
     for (let week of this._weeks) {
       let text = shortDateString(week.startDate)
                  + " - " + shortDateString(yesterday(week.endDate));
 
       let option = document.createElement("option");
       let content = document.createTextNode(text);
       option.appendChild(content);
       weekSelector.appendChild(option);
@@ -623,17 +622,16 @@ var EnvironmentData = {
     let table = document.createElement("table");
     table.setAttribute("id", sectionTitle);
     this.appendAddonSubsectionTitle(sectionTitle, table);
     this.appendRow(table, "persona", addonObj.persona);
     addonSection.appendChild(table);
   },
 
   renderActivePlugins: function(addonObj, addonSection, sectionTitle) {
-    let data = explodeObject(addonObj);
     let table = document.createElement("table");
     table.setAttribute("id", sectionTitle);
     this.appendAddonSubsectionTitle(sectionTitle, table);
 
     for (let plugin of addonObj) {
       let data = explodeObject(plugin);
       this.appendHeadingName(table, data.get("name"));
 

--- a/toolkit/content/aboutwebrtc/aboutWebrtc.js
+++ b/toolkit/content/aboutwebrtc/aboutWebrtc.js
@@ -267,17 +267,16 @@ AecLogging.prototype.offState = function
   } catch (e) {
     this._message = null;
   }
 };
 
 AecLogging.prototype.onState = function() {
   this._label = getString("aec_logging_on_state_label");
   try {
-    let file = Services.prefs.getCharPref("media.webrtc.debug.aec_log_dir");
     this._message = getString("aec_logging_on_state_msg");
   } catch (e) {
     this._message = null;
   }
 };
 
 AecLogging.prototype.onClick = function() {
   if (WebrtcGlobalInformation.aecDebug) {

--- a/toolkit/content/browser-content.js
+++ b/toolkit/content/browser-content.js
@@ -433,17 +433,16 @@ var Printing = {
       sendAsyncMessage("Printing:Error", {
         isPrinting: wbp.doingPrint,
         nsresult: nsresult,
       });
     }
   },
 
   receiveMessage(message) {
-    let objects = message.objects;
     let data = message.data;
     switch (message.name) {
       case "Printing:Preview:Enter": {
         this.enterPrintPreview(Services.wm.getOuterWindowWithId(data.windowID), data.simplifiedMode);
         break;
       }
 
       case "Printing:Preview:Exit": {
@@ -659,17 +658,16 @@ var Printing = {
   },
 
   exitPrintPreview() {
     docShell.printPreview.exitPrintPreview();
   },
 
   print(contentWindow, simplifiedMode) {
     let printSettings = this.getPrintSettings();
-    let rv = Cr.NS_OK;
 
     // If we happen to be on simplified mode, we need to set docURL in order
     // to generate header/footer content correctly, since simplified tab has
     // "about:blank" as its URI.
     if (printSettings && simplifiedMode) {
       printSettings.docURL = contentWindow.document.baseURI;
     }
 

--- a/toolkit/content/tests/browser/browser_bug1170531.js
+++ b/toolkit/content/tests/browser/browser_bug1170531.js
@@ -1,26 +1,15 @@
 // Test for bug 1170531
 // https://bugzilla.mozilla.org/show_bug.cgi?id=1170531
 
 add_task(function* () {
   // Get a bunch of DOM nodes
-  let winUtils = window.QueryInterface(Ci.nsIInterfaceRequestor).
-        getInterface(Ci.nsIDOMWindowUtils);
-
   let editMenu = document.getElementById("edit-menu");
-  let menubar = editMenu.parentNode;
   let menuPopup = editMenu.menupopup;
-  let editMenuIndex = -1;
-  for (let i = 0; i < menubar.children.length; i++) {
-    if (menubar.children[i] === editMenu) {
-      editMenuIndex = i;
-      break;
-    }
-  }
 
   let closeMenu = function(aCallback) {
     if (OS.Constants.Sys.Name == "Darwin") {
       executeSoon(aCallback);
       return;
     }
 
     menuPopup.addEventListener("popuphidden", function onPopupHidden() {

--- a/toolkit/content/tests/browser/browser_contentTitle.js
+++ b/toolkit/content/tests/browser/browser_contentTitle.js
@@ -1,13 +1,12 @@
 var url = "https://example.com/browser/toolkit/content/tests/browser/file_contentTitle.html";
 
 add_task(function*() {
   let tab = gBrowser.selectedTab = gBrowser.addTab(url);
-  let browser = tab.linkedBrowser;
   yield new Promise((resolve) => {
     addEventListener("TestLocationChange", function listener() {
       removeEventListener("TestLocationChange", listener);
       resolve();
     }, true, true);
   });
 
   is(gBrowser.contentTitle, "Test Page", "Should have the right title.");

--- a/toolkit/content/tests/browser/browser_crash_previous_frameloader.js
+++ b/toolkit/content/tests/browser/browser_crash_previous_frameloader.js
@@ -95,17 +95,17 @@ add_task(function* test_crash_in_previou
       setTimeout(() => {
         dump("\nEt tu, Brute?\n");
         dies();
       }, 0);
     });
 
     gBrowser.updateBrowserRemoteness(browser, false);
     info("Waiting for content process to go away.");
-    let [subject, data] = yield contentProcessGone;
+    let [subject /* , data */] = yield contentProcessGone;
 
     // If we don't clean up the minidump, the harness will
     // complain.
     cleanUpMinidump(subject);
 
     info("Content process is gone!");
     Assert.ok(!sawTabCrashed,
               "Should not have seen the oop-browser-crashed event.");

--- a/toolkit/content/tests/browser/browser_keyevents_during_autoscrolling.js
+++ b/toolkit/content/tests/browser/browser_keyevents_during_autoscrolling.js
@@ -7,17 +7,16 @@ add_task(function * ()
   const kKeyDownEvent  = 1;
   const kKeyPressEvent = 2;
   const kKeyUpEvent    = 4;
   const kAllKeyEvents  = 7;
 
   var expectedKeyEvents;
   var dispatchedKeyEvents;
   var key;
-  var root;
 
   /**
    * Encapsulates EventUtils.sendChar().
    */
   function sendChar(aChar)
   {
     key = aChar;
     dispatchedKeyEvents = kNoKeyEvents;

--- a/toolkit/content/tests/chrome/test_autocomplete_with_composition_on_input.html
+++ b/toolkit/content/tests/chrome/test_autocomplete_with_composition_on_input.html
@@ -33,23 +33,23 @@ function runTests()
   var target = document.getElementById("input");
 
   // Register a word to the form history.
   target.focus();
   target.value = "Mozilla";
   synthesizeKey("VK_RETURN", {});
   target.value = "";
 
-  var test1 = new nsDoTestsForAutoCompleteWithComposition(
+  new nsDoTestsForAutoCompleteWithComposition(
     "Testing on HTML input (asynchronously search)",
     window, target, formFillController.controller, is,
     function() { return target.value; },
     function() {
       target.setAttribute("timeout", 0);
-      var test2 = new nsDoTestsForAutoCompleteWithComposition(
+      new nsDoTestsForAutoCompleteWithComposition(
         "Testing on HTML input (synchronously search)",
         window, target, formFillController.controller, is,
         function() { return target.value; },
         function() {
           formFillController.timeout = originalFormFillTimeout;
           SpecialPowers.detachFormFillControllerFrom(window);
           SimpleTest.finish();
         });

--- a/toolkit/content/tests/chrome/xul_selectcontrol.js
+++ b/toolkit/content/tests/chrome/xul_selectcontrol.js
@@ -314,17 +314,17 @@ function test_nsIDOMXULSelectControlElem
   expectedValue = keyWrap ? "first" : "second";
   synthesizeKeyExpectEvent(forwardKey, {}, keyWrap ? element : null, "select", testid + "key down 2");
   test_nsIDOMXULSelectControlElement_States(element, testid + "key down 2", 2,
     expectedItem, expectedIndex, expectedValue);
 
   var thirditem = element.appendItem("Third Item", "third");
   var fourthitem = element.appendItem("Fourth Item", "fourth");
   if (behaviourContains(element.localName, "select-extended-keynav")) {
-    var fifthitem = element.appendItem("Fifth Item", "fifth");
+    element.appendItem("Fifth Item", "fifth");
     var sixthitem = element.appendItem("Sixth Item", "sixth");
 
     synthesizeKeyExpectEvent("VK_END", {}, element, "select", testid + "key end");
     test_nsIDOMXULSelectControlElement_States(element, testid + "key end", 6, sixthitem, 5, "sixth");
 
     synthesizeKeyExpectEvent("VK_HOME", {}, element, "select", testid + "key home");
     test_nsIDOMXULSelectControlElement_States(element, testid + "key home", 6, firstitem, 0, "first");
 

--- a/toolkit/content/tests/fennec-tile-testapp/chrome/content/BrowserView.js
+++ b/toolkit/content/tests/fennec-tile-testapp/chrome/content/BrowserView.js
@@ -170,27 +170,21 @@ function() {
 
   function getNewBatchOperationState() {
     return {
       viewportSizeChanged: false,
       dirtyAll: false
     };
   }
 
-  function clampViewportWH(width, height, visibleRect) {
-    let minW = visibleRect.width;
-    let minH = visibleRect.height;
-    return [Math.max(width, minW), Math.max(height, minH)];
-  }
-
-  function initContainer(container, visibleRect) {
-    container.style.width    = visibleRect.width  + 'px';
-    container.style.height   = visibleRect.height + 'px';
-    container.style.overflow = '-moz-hidden-unscrollable';
-  }
+  // function clampViewportWH(width, height, visibleRect) {
+  //   let minW = visibleRect.width;
+  //   let minH = visibleRect.height;
+  //   return [Math.max(width, minW), Math.max(height, minH)];
+  // }
 
   function resizeContainerToViewport(container, viewportRect) {
     container.style.width  = viewportRect.width  + 'px';
     container.style.height = viewportRect.height + 'px';
   }
 
   // !!! --- RESIZE HACK BEGIN -----
   function simulateMozAfterSizeChange(browser, width, height) {
@@ -252,17 +246,16 @@ function() {
 
     getVisibleRectX: function getVisibleRectX() { return this._visibleRect.x; },
     getVisibleRectY: function getVisibleRectY() { return this._visibleRect.y; },
     getVisibleRectWidth: function getVisibleRectWidth() { return this._visibleRect.width; },
     getVisibleRectHeight: function getVisibleRectHeight() { return this._visibleRect.height; },
 
     setViewportDimensions: function setViewportDimensions(width, height, causedByZoom) {
       let bvs = this._browserViewportState;
-      let vis = this._visibleRect;
 
       if (!bvs)
         return;
 
       // [width, height] = clampViewportWH(width, height, vis);
       bvs.viewportRect.right  = width;
       bvs.viewportRect.bottom = height;
 
@@ -325,19 +318,16 @@ function() {
 
     discardAllBatchOperations: function discardAllBatchOperations() {
       let bops = this._batchOps;
       while (bops.length > 0)
         this.discardBatchOperation();
     },
 
     moveVisibleBy: function moveVisibleBy(dx, dy) {
-      let vr = this._visibleRect;
-      let vs = this._browserViewportState;
-
       this.onBeforeVisibleMove(dx, dy);
       this.onAfterVisibleMove(dx, dy);
     },
 
     moveVisibleTo: function moveVisibleTo(x, y) {
       let visibleRect = this._visibleRect;
       let dx = x - visibleRect.x;
       let dy = y - visibleRect.y;
@@ -686,9 +676,8 @@ BrowserView.BrowserViewportState.prototy
                  '\tvisibleX='     + this.visibleX,
                  '\tvisibleY='     + this.visibleY,
                  '\tzoomLevel='    + this.zoomLevel];
 
     return '[BrowserViewportState] {\n' + props.join(',\n') + '\n}';
   }
 
 };
-

--- a/toolkit/content/tests/fennec-tile-testapp/chrome/content/FooScript.js
+++ b/toolkit/content/tests/fennec-tile-testapp/chrome/content/FooScript.js
@@ -104,17 +104,16 @@ BrowserView.prototype = {
   },
 
   resizeTileContainer: function resizeTileContainer() {
 
   },
 
   scrollboxToViewportRect: function scrollboxToViewportRect(rect, clip) {
     let leftbar  = this._leftbar.getBoundingClientRect();
-    let rightbar = this._rightbar.getBoundingClientRect();
     let topbar   = this._topbar.getBoundingClientRect();
 
     let xtrans = -leftbar.width;
     let ytrans = -topbar.height;
     let x = rect.x + xtrans;
     let y = rect.y + ytrans;
 
     // XXX we're cheating --- this is not really a clip, but its the only

--- a/toolkit/content/tests/fennec-tile-testapp/chrome/content/TileManager.js
+++ b/toolkit/content/tests/fennec-tile-testapp/chrome/content/TileManager.js
@@ -171,17 +171,16 @@ TileManager.prototype = {
     if (destCriticalRect) {
 
       let rect = destCriticalRect;
 
       let create = false;
 
       // this._tileCache.forEachIntersectingRect(destCriticalRect, false, appendNonDirtyTile, this);
       let visited = {};
-      let evictGuard = null;
       if (create) {
 	evictGuard = function evictGuard(tile) {
 	  return !visited[tile.toString()];
 	};
       }
 
       let starti = rect.left  >> kTileExponentWidth;
       let endi   = rect.right >> kTileExponentWidth;
@@ -823,18 +822,16 @@ TileManager.Tile.prototype = {
 
     let ctx = this._canvas.getContext("2d");
     ctx.save();
 
     browserView.browserToViewportCanvasContext(ctx);
 
     ctx.translate(x, y);
 
-    let cw = browserView._contentWindow;
-    // let cw = browser.contentWindow;
     ctx.asyncDrawXULElement(browserView._browser,
                    rect.left, rect.top,
                    rect.right - rect.left, rect.bottom - rect.top,
                    "grey",
                    (ctx.DRAWWINDOW_DO_NOT_FLUSH | ctx.DRAWWINDOW_DRAW_CARET));
 
     ctx.restore();
 

--- a/toolkit/content/tests/fennec-tile-testapp/chrome/content/WidgetStack.js
+++ b/toolkit/content/tests/fennec-tile-testapp/chrome/content/WidgetStack.js
@@ -584,18 +584,16 @@ WidgetStack.prototype = {
       this._viewportBounds.setBounds(arguments[0],
       arguments[1],
       arguments[2],
       arguments[3]);
     } else {
       throw "Invalid number of arguments to setViewportBounds";
     }
 
-    let vp = this._viewport;
-
     let dleft = this._viewportBounds.left - oldBounds.left;
     let dright = this._viewportBounds.right - oldBounds.right;
     let dtop = this._viewportBounds.top - oldBounds.top;
     let dbottom = this._viewportBounds.bottom - oldBounds.bottom;
 
     // log2("setViewportBounds dltrb", dleft, dtop, dright, dbottom);
 
     // move all vp-relative widgets to be the right offset from the bounds again
@@ -622,25 +620,23 @@ WidgetStack.prototype = {
 
     for (let bid in this._barriers) {
       let barrier = this._barriers[bid];
 
       // log2("setViewportBounds: looking at barrier", bid, barrier.vpRelative, barrier.type);
 
       if (barrier.vpRelative) {
         if (barrier.type == "vertical") {
-          let q = "v barrier moving from " + barrier.x + " to ";
           if (barrier.vpOffsetXBefore) {
             barrier.x += dleft;
           } else {
             barrier.x += dright;
           }
           // log2(q += barrier.x);
         } else if (barrier.type == "horizontal") {
-          let q = "h barrier moving from " + barrier.y + " to ";
           if (barrier.vpOffsetYBefore) {
             barrier.y += dtop;
           } else {
             barrier.y += dbottom;
           }
           // log2(q += barrier.y);
         }
       }
@@ -1235,18 +1231,16 @@ WidgetStack.prototype = {
   // If the widget goes to the left or above the viewport widget, then
   // vpOffsetXBefore or vpOffsetYBefore is set.
   // See setViewportBounds for use of vpOffset* state variables, and for how
   // the actual x and y coords of each widget are calculated based on their offsets
   // and the viewport bounds.
   _updateWidgets: function() {
     let vp = this._viewport;
 
-    let ofRect = this._viewingRect.clone();
-
     for (let wid in this._widgetState) {
       let state = this._widgetState[wid];
       if (vp && state.vpRelative) {
         // compute the vpOffset from 0,0 assuming that the viewport rect is 0,0
         if (state.rect.left >= vp.rect.right) {
           state.vpOffsetXBefore = false;
           state.vpOffsetX = state.rect.left - vp.rect.width;
         } else {
@@ -1371,18 +1365,16 @@ WidgetStack.prototype = {
     // t != "tb" && t != "bt" &&
 
     if (t != "horizontal" &&
         t != "vertical")
     {
       throw "Invalid barrier type: " + t;
     }
 
-    let x, y;
-
     let barrier = {};
     let vp = this._viewport;
 
     barrier.type = t;
 
     if (el.getAttribute("left"))
       barrier.x = parseInt(el.getAttribute("left"));
     else if (el.getAttribute("top"))

--- a/toolkit/content/tests/mochitest/test_mousecapture.xhtml
+++ b/toolkit/content/tests/mochitest/test_mousecapture.xhtml
@@ -1,18 +1,18 @@
 <?xml version="1.0"?>
 <!DOCTYPE HTML>
 <html xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
       xmlns="http://www.w3.org/1999/xhtml">
 <head>
   <title>Mouse Capture Tests</title>
   <link rel="stylesheet" href="chrome://global/skin/" type="text/css"/>
   <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script> 
-  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script> 
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
 </head>
 <body id="body" xmlns="http://www.w3.org/1999/xhtml">
   <p id="display"/><div id="content" style="display: none"/><pre id="test"/>
 
 <script><![CDATA[
 
 SimpleTest.expectAssertions(6, 12);
 
@@ -167,19 +167,16 @@ function runTests()
   synthesizeMouse(image, 2, 2, { type: "mouseup" });
 
   window.scroll(0, 0);
 
   // save scroll
   var scrollX = parent ? parent.scrollX : 0;
   var scrollY = parent ? parent.scrollY : 0;
 
-  var b = frames[0].document.getElementById("b");
-//  runCaptureTest(b, selectionCallback);
-
   // restore scroll
   if (parent) parent.scroll(scrollX, scrollY);
 
 //  frames[0].getSelection().collapseToStart();
 
   var body = frames[0].document.body;
   var fixed = frames[0].document.getElementById("fixed");
   function captureOnBody() { body.setCapture() }
@@ -331,9 +328,8 @@ SimpleTest.waitForFocus(runTests);
   <img id="image" xmlns="http://www.w3.org/1999/xhtml"
        onmousedown="this.setCapture();" onmouseup="this.releaseCapture();"
        ondragstart="ok(false, 'should not get a drag when a setCapture is active');"
        src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAIAAAAC64paAAAAG0lEQVR42mP8z0A%2BYKJA76jmUc2jmkc1U0EzACKcASfOgGoMAAAAAElFTkSuQmCC"/>
 
 </body>
 
 </html>
-

--- a/toolkit/content/tests/widgets/tree_shared.js
+++ b/toolkit/content/tests/widgets/tree_shared.js
@@ -620,17 +620,16 @@ function testtag_tree_TreeSelection_UI(t
 
 function testtag_tree_UI_editing(tree, testid, rowInfo)
 {
   testid += " editing UI ";
 
   // check editing UI
   var ecolumn = tree.columns[0];
   var rowIndex = 2;
-  var inputField = tree.inputField;
 
   // temporary make the tree editable to test mouse double click
   var wasEditable = tree.editable;
   if (!wasEditable)
     tree.editable = true;
 
   // if this is a container save its current open status
   var row = rowInfo.rows[rowIndex];
@@ -918,17 +917,16 @@ function testtag_tree_TreeView_rows(tree
     isEditable: function(row, cell) { return cell.editable },
     isSelectable: function(row, cell) { return cell.selectable },
     getImageSrc: function(row, cell) { return cell.image },
     getProgressMode: function(row, cell) { return cell.mode }
   };
 
   var failedMethods = { };
   var checkMethod, actual, expected;
-  var containerInfo = null;
   var toggleOpenStateOK = true;
 
   for (r = startRow; r < length; r++) {
     var row = rowInfo.rows[r];
     for (var c = 0; c < row.cells.length; c++) {
       var cell = row.cells[c];
 
       for (checkMethod in checkCellMethods) {

--- a/toolkit/content/treeUtils.js
+++ b/toolkit/content/treeUtils.js
@@ -53,26 +53,24 @@ var gTreeUtils = {
 
   sort: function(aTree, aView, aDataSet, aColumn, aComparator,
                  aLastSortColumn, aLastSortAscending)
   {
     var ascending = (aColumn == aLastSortColumn) ? !aLastSortAscending : true;
     if (aDataSet.length == 0)
       return ascending;
 
-    var numericSort = !isNaN(aDataSet[0][aColumn]);
     var sortFunction = null;
     if (aComparator) {
       sortFunction = function(a, b) { return aComparator(a[aColumn], b[aColumn]); };
     }
     aDataSet.sort(sortFunction);
     if (!ascending)
       aDataSet.reverse();
 
     aTree.view.selection.clearSelection();
     aTree.view.selection.select(0);
     aTree.treeBoxObject.invalidate();
     aTree.treeBoxObject.ensureRowIsVisible(0);
 
     return ascending;
   }
 };
-

--- a/toolkit/content/widgets/browser.xml
+++ b/toolkit/content/widgets/browser.xml
@@ -939,17 +939,18 @@
                 }
               }
             }
           }
           catch (e) {
             Components.utils.reportError(e);
           }
           try {
-            var securityUI = this.securityUI;
+            // Ensures the securityUI is initialized.
+            var securityUI = this.securityUI; // eslint-disable-line no-unused-vars
           }
           catch (e) {
           }
 
           // XXX tabbrowser.xml sets "relatedBrowser" as a direct property on
           // some browsers before they are put into a DOM (and get a binding).
           // This hack makes sure that we hold a weak reference to the other
           // browser (and go through the proper getter and setter).
@@ -1564,17 +1565,16 @@
       </handler>
       <handler event="drop" group="system">
       <![CDATA[
         // No need to handle "drop" in e10s, since nsDocShellTreeOwner.cpp in the child process
         // handles that case using "@mozilla.org/content/dropped-link-handler;1" service.
         if (!this.droppedLinkHandler || event.defaultPrevented || this.isRemoteBrowser)
           return;
 
-        let name = { };
         let linkHandler = Components.classes["@mozilla.org/content/dropped-link-handler;1"].
                             getService(Components.interfaces.nsIDroppedLinkHandler);
         try {
           // Pass true to prevent the dropping of javascript:/data: URIs
           var links = linkHandler.dropLinks(event, true);
         } catch (ex) {
           return;
         }

--- a/toolkit/content/widgets/popup.xml
+++ b/toolkit/content/widgets/popup.xml
@@ -396,18 +396,16 @@
         <![CDATA[
           this.popupBoxObject.moveToAnchor(aAnchorElement, aPosition, aX, aY, aAttributesOverride);
         ]]>
         </body>
       </method>
       <method name="adjustArrowPosition">
         <body>
         <![CDATA[
-        var arrow = document.getAnonymousElementByAttribute(this, "anonid", "arrow");
-
         var anchor = this.anchorNode;
         if (!anchor) {
           return;
         }
 
         var container = document.getAnonymousElementByAttribute(this, "anonid", "container");
         var arrowbox = document.getAnonymousElementByAttribute(this, "anonid", "arrowbox");
 

--- a/toolkit/content/widgets/preferences.xml
+++ b/toolkit/content/widgets/preferences.xml
@@ -1063,18 +1063,16 @@
         if (!this._fireEvent("beforeaccept", this)) {
           return false;
         }
 
         var secMan = Components.classes["@mozilla.org/scriptsecuritymanager;1"]
                     .getService(Components.interfaces.nsIScriptSecurityManager);
         if (this.type == "child" && window.opener &&
             secMan.isSystemPrincipal(window.opener.document.nodePrincipal)) {
-          let psvc = Components.classes["@mozilla.org/preferences-service;1"]
-                               .getService(Components.interfaces.nsIPrefBranch);
           var pdocEl = window.opener.document.documentElement;
           if (pdocEl.instantApply) {
             let panes = this.preferencePanes;
             for (let i = 0; i < panes.length; ++i)
               panes[i].writePreferences(true);
           }
           else {
             // Clone all the preferences elements from the child document and

--- a/toolkit/content/widgets/spinner.js
+++ b/toolkit/content/widgets/spinner.js
@@ -13,17 +13,16 @@
  */
 
 function Spinner(props, context) {
   this.context = context;
   this._init(props);
 }
 
 {
-  const debug = 0 ? console.log.bind(console, "[spinner]") : function() {};
 
   const ITEM_HEIGHT = 2.5,
         VIEWPORT_SIZE = 7,
         VIEWPORT_COUNT = 5,
         SCROLL_TIMEOUT = 100;
 
   Spinner.prototype = {
     /**
@@ -91,17 +90,16 @@ function Spinner(props, context) {
      *          {Number/String} value: The centered value
      *          {Array} items: The list of items for display
      *          {Boolean} isInfiniteScroll: Whether or not the spinner should
      *            have infinite scroll capability
      *          {Boolean} isValueSet: true if user has selected a value
      *        }
      */
     setState(newState) {
-      const { spinner } = this.elements;
       const { value, items } = this.state;
       const { value: newValue, items: newItems, isValueSet, isInvalid } = newState;
 
       if (this._isArrayDiff(newItems, items)) {
         this.state = Object.assign(this.state, newState);
         this._updateItems();
         this._scrollTo(newValue, true);
       } else if (newValue != value) {
@@ -124,17 +122,17 @@ function Spinner(props, context) {
      * - If a smooth scroll has reached its destination, set [isScrolling] state
      *   to false
      * - If the value has changed, update the [value] state and call [setValue]
      * - If infinite scrolling is on, reset the scrolling position if necessary
      */
     _onScroll() {
       const { items, itemsView, isInfiniteScroll } = this.state;
       const { viewportSize, viewportTopOffset } = this.props;
-      const { spinner, itemsViewElements } = this.elements;
+      const { spinner } = this.elements;
 
       this.state.index = this._getIndexByOffset(spinner.scrollTop);
 
       const value = itemsView[this.state.index + viewportTopOffset].value;
 
       // Check if smooth scrolling has reached its destination.
       // This prevents input box jump when input box changes values.
       if (this.state.value == value && this.state.isScrolling) {

--- a/toolkit/content/widgets/tabbox.xml
+++ b/toolkit/content/widgets/tabbox.xml
@@ -26,17 +26,17 @@
         ]]>
         </setter>
         <getter>
         <![CDATA[
           return (this.getAttribute("handleCtrlTab") != "false");
         ]]>
         </getter>
       </property>
-      
+
       <property name="handleCtrlPageUpDown">
         <setter>
         <![CDATA[
           this.setAttribute("handleCtrlPageUpDown", val);
           return val;
         ]]>
         </setter>
         <getter>
@@ -69,17 +69,17 @@
         <getter>
         <![CDATA[
           return this.getElementsByTagNameNS(
               "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul",
               "tabpanels").item(0);
         ]]>
         </getter>
       </property>
-      
+
       <property name="selectedIndex">
         <getter>
         <![CDATA[
           var tabs = this.tabs;
           return tabs ? tabs.selectedIndex : -1;
         ]]>
         </getter>
 
@@ -239,17 +239,17 @@
       <stylesheet src="chrome://global/skin/tabbox.css"/>
     </resources>
 
     <content>
       <xul:spacer class="tabs-left"/>
       <children/>
       <xul:spacer class="tabs-right" flex="1"/>
     </content>
-    
+
     <implementation implements="nsIDOMXULSelectControlElement, nsIDOMXULRelatedElement">
       <constructor>
       <![CDATA[
         // first and last tabs need to be able to have unique styles
         // and also need to select first tab on startup.
         if (this.firstChild)
           this.firstChild.setAttribute("first-tab", "true");
         if (this.lastChild)
@@ -294,18 +294,16 @@
             return null;
 
           let tabpanelsElm = tabboxElm.tabpanels;
           if (!tabpanelsElm)
             return null;
 
           // Get linked tab panel by 'linkedpanel' attribute on the given tab
           // element.
-          let linkedPanelElm = null;
-
           let linkedPanelId = aTabElm.linkedPanel;
           if (linkedPanelId) {
             let ownerDoc = this.ownerDocument;
 
             // XXX bug 565858: if XUL tab element is anonymous element then
             // suppose linked tab panel is hosted within the same XBL binding
             // and search it by ID attribute inside an anonymous content of
             // the binding. This is not robust assumption since tab elements may
@@ -381,17 +379,17 @@
           const tabs = this.childNodes;
           for (var i = 0; i < tabs.length; i++) {
             if (tabs[i].selected)
               return i;
           }
           return -1;
         ]]>
         </getter>
-        
+
         <setter>
         <![CDATA[
           var tab = this.getItemAtIndex(val);
           if (tab) {
             var alreadySelected = tab.selected;
 
             Array.forEach(this.childNodes, function(aTab) {
               if (aTab.selected && aTab != tab)
@@ -546,17 +544,17 @@
           var tab = document.createElementNS(XULNS, "tab");
           tab.setAttribute("label", label);
           tab.setAttribute("value", value);
           this.appendChild(tab);
           return tab;
         ]]>
         </body>
       </method>
-      
+
       <method name="insertItemAt">
         <parameter name="index"/>
         <parameter name="label"/>
         <parameter name="value"/>
         <body>
         <![CDATA[
           var XULNS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
           var tab = document.createElementNS(XULNS, "tab");
@@ -884,9 +882,8 @@
         var tabs = this.parentNode.childNodes;
         this.parentNode._selectNewTab(tabs[tabs.length - 1], -1);
       ]]>
       </handler>
     </handlers>
   </binding>
 
 </bindings>
-

--- a/toolkit/content/widgets/timekeeper.js
+++ b/toolkit/content/widgets/timekeeper.js
@@ -19,18 +19,16 @@
  *        }
  */
 function TimeKeeper(props) {
   this.props = props;
   this.state = { time: new Date(0), ranges: {} };
 }
 
 {
-  const debug = 0 ? console.log.bind(console, '[timekeeper]') : function() {};
-
   const DAY_PERIOD_IN_HOURS = 12,
         SECOND_IN_MS = 1000,
         MINUTE_IN_MS = 60000,
         HOUR_IN_MS = 3600000,
         DAY_PERIOD_IN_MS = 43200000,
         DAY_IN_MS = 86400000,
         TIME_FORMAT_24 = "24";
 

--- a/toolkit/content/widgets/timepicker.js
+++ b/toolkit/content/widgets/timepicker.js
@@ -5,18 +5,16 @@
 "use strict";
 
 function TimePicker(context) {
   this.context = context;
   this._attachEventListeners();
 }
 
 {
-  const debug = 0 ? console.log.bind(console, "[timepicker]") : function() {};
-
   const DAY_PERIOD_IN_HOURS = 12,
         SECOND_IN_MS = 1000,
         MINUTE_IN_MS = 60000,
         DAY_IN_MS = 86400000;
 
   TimePicker.prototype = {
     /**
      * Initializes the time picker. Set the default states and properties.
@@ -73,17 +71,17 @@ function TimePicker(context) {
       let time = new Date("1970-01-01T" + timeString + "Z");
       return time.toString() == "Invalid Date" ? false : time;
     },
 
     /**
      * Initalize the spinner components.
      */
     _createComponents() {
-      const { locale, step, format } = this.props;
+      const { locale, format } = this.props;
       const { timeKeeper } = this.state;
 
       const wrapSetValueFn = (setTimeFunction) => {
         return (value) => {
           setTimeFunction(value);
           this._setComponentStates();
           this._dispatchState();
         };

--- a/toolkit/crashreporter/CrashSubmit.jsm
+++ b/toolkit/crashreporter/CrashSubmit.jsm
@@ -396,17 +396,17 @@ Submitter.prototype = {
         this.extraKeyVals[key] = extraKeyVals[key];
       }
     }
 
     let additionalDumps = [];
     if ("additional_minidumps" in this.extraKeyVals) {
       let names = this.extraKeyVals.additional_minidumps.split(',');
       for (let name of names) {
-        let [dump, extra, memory] = getPendingMinidump(this.id + "-" + name);
+        let [dump /* , extra, memory */] = getPendingMinidump(this.id + "-" + name);
         if (!dump.exists()) {
           this.notifyStatus(FAILED);
           this.cleanup();
           return this.deferredSubmit.promise;
         }
         additionalDumps.push({'name': name, 'dump': dump});
       }
     }
@@ -449,18 +449,16 @@ this.CrashSubmit = {
    *
    *  @return a Promise that is fulfilled with the server crash ID when the
    *          submission succeeds and rejected otherwise.
    */
   submit: function CrashSubmit_submit(id, params)
   {
     params = params || {};
     let recordSubmission = false;
-    let submitSuccess = null;
-    let submitError = null;
     let noThrottle = false;
     let extraExtraKeyVals = null;
 
     if ('recordSubmission' in params)
       recordSubmission = params.recordSubmission;
     if ('noThrottle' in params)
       noThrottle = params.noThrottle;
     if ('extraExtraKeyVals' in params)
@@ -491,17 +489,17 @@ this.CrashSubmit = {
    * Add a .dmg.ignore file along side the .dmp file to indicate that the user
    * shouldn't be prompted to submit this crash report again.
    *
    * @param id
    *        Filename (minus .dmp extension) of the report to ignore
    */
 
   ignore: function CrashSubmit_ignore(id) {
-    let [dump, extra, mem] = getPendingMinidump(id);
+    let [dump /* , extra, memory */] = getPendingMinidump(id);
     return OS.File.open(dump.path + ".ignore", {create: true},
                         {unixFlags: OS.Constants.libc.O_CREAT})
       .then((file) => { file.close(); });
   },
 
   /**
    * Get the list of pending crash IDs.
    *

--- a/toolkit/crashreporter/test/unit/test_crashreporter.js
+++ b/toolkit/crashreporter/test/unit/test_crashreporter.js
@@ -3,17 +3,17 @@ function run_test()
   dump("INFO | test_crashreporter.js | Get crashreporter service.\n");
   var cr = Components.classes["@mozilla.org/toolkit/crash-reporter;1"]
                      .getService(Components.interfaces.nsICrashReporter);
   do_check_neq(cr, null);
 
   do_check_true(cr.enabled);
 
   try {
-    let su = cr.serverURL;
+    cr.serverURL;
     do_throw("Getting serverURL when not set should have thrown!");
   }
   catch (ex) {
     do_check_eq(ex.result, Components.results.NS_ERROR_FAILURE);
   }
 
   // check setting/getting serverURL
   var ios = Components.classes["@mozilla.org/network/io-service;1"]

--- a/toolkit/crashreporter/test/unit/test_crashreporter_crash_profile_lock.js
+++ b/toolkit/crashreporter/test/unit/test_crashreporter_crash_profile_lock.js
@@ -11,16 +11,16 @@ function run_test()
   do_crash(function() {
              let env = Components.classes["@mozilla.org/process/environment;1"]
                .getService(Components.interfaces.nsIEnvironment);
              // the python harness sets this in the environment for us
              let profd = env.get("XPCSHELL_TEST_PROFILE_DIR");
              let dir = Components.classes["@mozilla.org/file/local;1"]
                .createInstance(Components.interfaces.nsILocalFile);
              dir.initWithPath(profd);
-             let lock = CrashTestUtils.lockDir(dir);
+             CrashTestUtils.lockDir(dir);
              // when we crash, the lock file should be cleaned up
            },
            function(mdump, extra) {
              // if we got here, we have a minidump, so that's all we wanted
              do_check_true(true);
            });
 }

--- a/toolkit/forgetaboutsite/ForgetAboutSite.jsm
+++ b/toolkit/forgetaboutsite/ForgetAboutSite.jsm
@@ -88,17 +88,16 @@ this.ForgetAboutSite = {
     // Plugin data
     const phInterface = Ci.nsIPluginHost;
     const FLAG_CLEAR_ALL = phInterface.FLAG_CLEAR_ALL;
     let ph = Cc["@mozilla.org/plugin/host;1"].getService(phInterface);
     let tags = ph.getPluginTags();
     let promises = [];
     for (let i = 0; i < tags.length; i++) {
       let promise = new Promise(resolve => {
-        let tag = tags[i];
         try {
           ph.clearSiteData(tags[i], aDomain, FLAG_CLEAR_ALL, -1, function(rv) {
             resolve();
           });
         } catch (e) {
           // Ignore errors from the plugin, but resolve the promise
           resolve();
         }

--- a/toolkit/forgetaboutsite/test/unit/test_removeDataFromDomain.js
+++ b/toolkit/forgetaboutsite/test/unit/test_removeDataFromDomain.js
@@ -484,17 +484,17 @@ function* test_push_cleared()
            getService(Ci.nsIPushService);
   } catch (e) {
     // No push service, skip test.
     return;
   }
 
   do_get_profile();
   setPrefs();
-  const {PushDB, PushService, PushServiceWebSocket} = serviceExports;
+  const {PushService, PushServiceWebSocket} = serviceExports;
   const userAgentID = 'bd744428-f125-436a-b6d0-dd0c9845837f';
   const channelID = '0ef2ad4a-6c49-41ad-af6e-95d2425276bf';
 
   let db = PushServiceWebSocket.newPushDB();
 
   try {
     PushService.init({
       serverURI: "wss://push.example.org/",

--- a/toolkit/identity/IdentityProvider.jsm
+++ b/toolkit/identity/IdentityProvider.jsm
@@ -173,17 +173,16 @@ IdentityProviderService.prototype = {
 
     // Expect a flow for this caller already to be underway.
     let provFlow = this.getProvisionFlow(aCaller.id, aCaller.doError);
 
     // keep the caller object around
     provFlow.caller = aCaller;
 
     let identity = provFlow.identity;
-    let frame = provFlow.provisioningFrame;
 
     // Determine recommended length of cert.
     let duration = this.certDuration;
 
     // Make a record that we have begun provisioning.  This is required
     // for genKeyPair.
     provFlow.didBeginProvisioning = true;
 

--- a/toolkit/identity/LogUtils.jsm
+++ b/toolkit/identity/LogUtils.jsm
@@ -82,18 +82,16 @@ IdentityLogger.prototype = {
     Services.console.logStringMessage(output);
   },
 
   /**
    * reportError() - report an error through component utils as well as
    * our log function
    */
   reportError: function reportError(aPrefix, ...aArgs) {
-    let prefix = aPrefix + ' ERROR';
-
     // Report the error in the browser
     let output = this._generateLogMessage(aPrefix, aArgs);
     Cu.reportError(output);
     dump("ERROR: " + output + "\n");
     for (let frame = Components.stack.caller; frame; frame = frame.caller) {
       dump(frame + "\n");
     }
   }

--- a/toolkit/identity/tests/unit/test_firefox_accounts.js
+++ b/toolkit/identity/tests/unit/test_firefox_accounts.js
@@ -175,18 +175,16 @@ function test_logout() {
   withSomebodySignedIn().then(() => {
     FirefoxAccounts.RP.watch(mockedRP);
   });
 }
 
 function test_error() {
   do_test_pending();
 
-  let received = [];
-
   // Mock the fxAccountsManager so that getAssertion rejects its promise and
   // triggers our onerror handler.  (This is the method that's used internally
   // by FirefoxAccounts.RP.request().)
   let originalGetAssertion = FirefoxAccounts.fxAccountsManager.getAssertion;
   FirefoxAccounts.fxAccountsManager.getAssertion = function(audience) {
     return Promise.reject(new Error("barf!"));
   };
 

--- a/toolkit/identity/tests/unit/test_jwcrypto.js
+++ b/toolkit/identity/tests/unit/test_jwcrypto.js
@@ -210,17 +210,17 @@ function test_audience_encoding_bug97258
   jwcrypto.generateKeyPair(
     "DS160",
     function(err, kp) {
       do_check_null(err);
       jwcrypto.generateAssertion("fake-cert", kp, audience,
         function(err2, backedAssertion) {
           do_check_null(err2);
 
-          let [cert, assertion] = backedAssertion.split("~");
+          let [/* cert */, assertion] = backedAssertion.split("~");
           let components = extractComponents(assertion);
           do_check_eq(components.payload.aud, audience);
 
           do_test_finished();
           run_next_test();
         }
       );
     }

--- a/toolkit/identity/tests/unit/test_log_utils.js
+++ b/toolkit/identity/tests/unit/test_log_utils.js
@@ -23,17 +23,17 @@ function toggle_debug() {
       }
     },
 
     init: function() {
       Services.prefs.addObserver('toolkit.identity.debug', this, false);
     }
   };
 
-  var wrapper = new Wrapper();
+  new Wrapper();
   Services.prefs.setBoolPref('toolkit.identity.debug', true);
 }
 
 // test that things don't break
 
 function logAlias(...args) {
   Logger.log.apply(Logger, ["log alias"].concat(args));
 }

--- a/toolkit/modules/DateTimePickerHelper.jsm
+++ b/toolkit/modules/DateTimePickerHelper.jsm
@@ -105,17 +105,16 @@ this.DateTimePickerHelper = {
       browser.messageManager.sendAsyncMessage(
         "FormDateTime:PickerValueChanged", { hour, minute });
     }
   },
 
   // Get picker from browser and show it anchored to the input box.
   showPicker: function(aBrowser, aData) {
     let rect = aData.rect;
-    let dir = aData.dir;
     let type = aData.type;
     let detail = aData.detail;
 
     this._anchor = aBrowser.ownerGlobal.gBrowser.popupAnchor;
     this._anchor.left = rect.left;
     this._anchor.top = rect.top;
     this._anchor.width = rect.width;
     this._anchor.height = rect.height;

--- a/toolkit/modules/Finder.jsm
+++ b/toolkit/modules/Finder.jsm
@@ -412,17 +412,16 @@ Finder.prototype = {
         this.searchString == "" || !aWord || !this.matchesCountLimit) {
       this._notifyMatchesCount({
         total: 0,
         current: 0
       });
       return;
     }
 
-    let window = this._getWindow();
     this._currentFoundRange = this._fastFind.getFoundRange();
 
     let params = {
       caseSensitive: this._fastFind.caseSensitive,
       entireWord: this._fastFind.entireWord,
       linksOnly: aLinksOnly,
       word: aWord
     };

--- a/toolkit/modules/FinderHighlighter.jsm
+++ b/toolkit/modules/FinderHighlighter.jsm
@@ -1489,18 +1489,16 @@ FinderHighlighter.prototype = {
   },
 
   WillDeleteSelection(selection) {
     let editor = this._getEditableNode(selection.getRangeAt(0)
                                                  .startContainer).editor;
     let controller = editor.selectionController;
     let fSelection = controller.getSelection(Ci.nsISelectionController.SELECTION_FIND);
 
-    let selectionIndex = 0;
-    let findSelectionIndex = 0;
     let shouldDelete = {};
     let numberOfDeletedSelections = 0;
     let numberOfMatches = fSelection.rangeCount;
 
     // We need to test if any ranges in the deleted selection (selection)
     // are in any of the ranges of the find selection
     // Usually both selections will only contain one range, however
     // either may contain more than one.

--- a/toolkit/modules/FinderIterator.jsm
+++ b/toolkit/modules/FinderIterator.jsm
@@ -448,17 +448,17 @@ this.FinderIterator = {
       // During the timeout, we could have gotten the signal to stop iterating.
       // Make sure we do here.
       if (!this.running || spawnId !== this._spawnId)
         return;
     }
 
     this._notifyListeners("start", this.params);
 
-    let { linksOnly, window, word } = this._currentParams;
+    let { linksOnly, window } = this._currentParams;
     // First we collect all frames we need to search through, whilst making sure
     // that the parent window gets dibs.
     let frames = [window].concat(this._collectFrames(window, finder));
     let iterCount = 0;
     for (let frame of frames) {
       for (let range of this._iterateDocument(this._currentParams, frame)) {
         // Between iterations, for example after a sleep of one cycle, we could
         // have gotten the signal to stop iterating. Make sure we do here.

--- a/toolkit/modules/InlineSpellChecker.jsm
+++ b/toolkit/modules/InlineSpellChecker.jsm
@@ -214,17 +214,16 @@ InlineSpellChecker.prototype = {
       list = this.mRemote.dictionaryList;
       curlang = this.mRemote.currentDictionary;
     }
     else if (this.mInlineSpellChecker) {
       var spellchecker = this.mInlineSpellChecker.spellChecker;
       var o1 = {}, o2 = {};
       spellchecker.GetDictionaryList(o1, o2);
       list = o1.value;
-      var listcount = o2.value;
       try {
         curlang = spellchecker.GetCurrentDictionary();
       } catch (e) {}
     }
 
     var sortedList = this.sortDictionaryList(list);
 
     for (var i = 0; i < sortedList.length; i++) {
@@ -258,17 +257,17 @@ InlineSpellChecker.prototype = {
     return list.length;
   },
 
   // Formats a valid BCP 47 language tag based on available localized names.
   getDictionaryDisplayName: function(dictionaryName) {
     try {
       // Get the display name for this dictionary.
       let languageTagMatch = /^([a-z]{2,3}|[a-z]{4}|[a-z]{5,8})(?:[-_]([a-z]{4}))?(?:[-_]([A-Z]{2}|[0-9]{3}))?((?:[-_](?:[a-z0-9]{5,8}|[0-9][a-z0-9]{3}))*)(?:[-_][a-wy-z0-9](?:[-_][a-z0-9]{2,8})+)*(?:[-_]x(?:[-_][a-z0-9]{1,8})+)?$/i;
-      var [languageTag, languageSubtag, scriptSubtag, regionSubtag, variantSubtags] = dictionaryName.match(languageTagMatch);
+      var [/* languageTag */, languageSubtag, scriptSubtag, regionSubtag, variantSubtags] = dictionaryName.match(languageTagMatch);
     } catch (e) {
       // If we weren't given a valid language tag, just use the raw dictionary name.
       return dictionaryName;
     }
 
     if (!gLanguageBundle) {
       // Create the bundles for language and region names.
       var bundleService = Components.classes["@mozilla.org/intl/stringbundle;1"]

--- a/toolkit/modules/NewTabUtils.jsm
+++ b/toolkit/modules/NewTabUtils.jsm
@@ -904,17 +904,17 @@ var Links = {
           } catch (e) {
             // We want to proceed even if a callback fails.
           }
         }
       }
     }
 
     let numProvidersRemaining = this._providers.size;
-    for (let [provider, links] of this._providers) {
+    for (let [provider /* , links */] of this._providers) {
       this._populateProviderCache(provider, () => {
         if (--numProvidersRemaining == 0)
           executeCallbacks();
       }, aForce);
     }
 
     this._addObserver();
   },
@@ -1017,17 +1017,17 @@ var Links = {
     * to increment or decrement it. We do this by iterating over all stored providers
     * to find which provider this link already exists in. For providers that
     * have this link, we will adjust siteMap for them accordingly.
     *
     * @param aLink The link that will affect siteMap
     * @param increment A boolean for whether to increment or decrement siteMap
     */
   _adjustSiteMapAndNotify: function(aLink, increment = true) {
-    for (let [provider, cache] of this._providers) {
+    for (let [/* provider */, cache] of this._providers) {
       // We only update siteMap if aLink is already stored in linkMap.
       if (cache.linkMap.get(aLink.url)) {
         if (increment) {
           this._incrementSiteMap(cache.siteMap, aLink);
           continue;
         }
         this._decrementSiteMap(cache.siteMap, aLink);
       }

--- a/toolkit/modules/PageMenu.jsm
+++ b/toolkit/modules/PageMenu.jsm
@@ -16,17 +16,16 @@ PageMenu.prototype = {
   _popup: null,
 
   // Only one of builder or browser will end up getting set.
   _builder: null,
   _browser: null,
 
   // Given a target node, get the context menu for it or its ancestor.
   getContextMenu: function(aTarget) {
-    let pageMenu = null;
     let target = aTarget;
     while (target) {
       let contextMenu = target.contextMenu;
       if (contextMenu) {
         return contextMenu;
       }
       target = target.parentNode;
     }

--- a/toolkit/modules/RemotePageManager.jsm
+++ b/toolkit/modules/RemotePageManager.jsm
@@ -509,17 +509,17 @@ var observer = (window) => {
 
   // Get the frame message manager for this window so we can associate this
   // page with a browser element
   let messageManager = window.QueryInterface(Ci.nsIInterfaceRequestor)
                              .getInterface(Ci.nsIDocShell)
                              .QueryInterface(Ci.nsIInterfaceRequestor)
                              .getInterface(Ci.nsIContentFrameMessageManager);
   // Set up the child side of the message port
-  let port = new ChildMessagePort(messageManager, window);
+  new ChildMessagePort(messageManager, window);
 };
 Services.obs.addObserver(observer, "chrome-document-global-created", false);
 Services.obs.addObserver(observer, "content-document-global-created", false);
 
 // A message from chrome telling us what pages to listen for
 Services.cpmm.addMessageListener("RemotePage:Register", ({ data }) => {
   for (let url of data.urls)
     registeredURLs.add(url);

--- a/toolkit/modules/SelectContentHelper.jsm
+++ b/toolkit/modules/SelectContentHelper.jsm
@@ -202,18 +202,16 @@ this.SelectContentHelper.prototype = {
 
 function getComputedStyles(element) {
   return element.ownerDocument.defaultView.getComputedStyle(element);
 }
 
 function buildOptionListForChildren(node) {
   let result = [];
 
-  let win = node.ownerDocument.defaultView;
-
   for (let child of node.children) {
     let tagName = child.tagName.toUpperCase();
 
     if (tagName == 'OPTION' || tagName == 'OPTGROUP') {
       if (child.hidden) {
         continue;
       }
 

--- a/toolkit/modules/SelectParentHelper.jsm
+++ b/toolkit/modules/SelectParentHelper.jsm
@@ -139,18 +139,16 @@ this.SelectParentHelper = {
       case "keydown":
         if (event.keyCode == event.DOM_VK_RETURN) {
           closedWithEnter = true;
         }
         break;
 
       case "command":
         if (event.target.hasAttribute("value")) {
-          let win = currentBrowser.ownerDocument.defaultView;
-
           currentBrowser.messageManager.sendAsyncMessage("Forms:SelectDropDownItem", {
             value: event.target.value,
             closedWithEnter: closedWithEnter
           });
         }
         break;
 
       case "fullscreen":

--- a/toolkit/modules/SpatialNavigation.jsm
+++ b/toolkit/modules/SpatialNavigation.jsm
@@ -244,17 +244,16 @@ function _getRootBounds(windowUtils) {
   return cssPageRectCopy;
 }
 
 // Returns the best node to focus from the list of nodes returned by the hit
 // test.
 function _getBestToFocus(nodes, key, currentlyFocused) {
   let best = null;
   let bestDist;
-  let bestMid;
   let nodeMid;
   let currentlyFocusedMid = _getMidpoint(currentlyFocused);
   let currentlyFocusedRect = currentlyFocused.getBoundingClientRect();
 
   for (let i = 0; i < nodes.length; i++) {
     // Reject the currentlyFocused, and all node types we can't focus
     if (!_canFocus(nodes[i]) || nodes[i] === currentlyFocused) {
       continue;

--- a/toolkit/modules/Sqlite.jsm
+++ b/toolkit/modules/Sqlite.jsm
@@ -422,31 +422,31 @@ ConnectionData.prototype = Object.freeze
     return cloneStorageConnection(options);
   },
   _getOperationId: function() {
     return this._operationsCounter++;
   },
   _finalize: function() {
     this._log.debug("Finalizing connection.");
     // Cancel any pending statements.
-    for (let [k, statement] of this._pendingStatements) {
+    for (let [/* k */, statement] of this._pendingStatements) {
       statement.cancel();
     }
     this._pendingStatements.clear();
 
     // We no longer need to track these.
     this._statementCounter = 0;
 
     // Next we finalize all active statements.
-    for (let [k, statement] of this._anonymousStatements) {
+    for (let [/* k */, statement] of this._anonymousStatements) {
       statement.finalize();
     }
     this._anonymousStatements.clear();
 
-    for (let [k, statement] of this._cachedStatements) {
+    for (let [/* k */, statement] of this._cachedStatements) {
       statement.finalize();
     }
     this._cachedStatements.clear();
 
     // This guards against operations performed between the call to this
     // function and asyncClose() finishing. See also bug 726990.
     this._open = false;
 
@@ -656,17 +656,17 @@ ConnectionData.prototype = Object.freeze
   shrinkMemory: function() {
     this._log.info("Shrinking memory usage.");
     let onShrunk = this._clearIdleShrinkTimer.bind(this);
     return this.execute("PRAGMA shrink_memory").then(onShrunk, onShrunk);
   },
 
   discardCachedStatements: function() {
     let count = 0;
-    for (let [k, statement] of this._cachedStatements) {
+    for (let [/* k */, statement] of this._cachedStatements) {
       ++count;
       statement.finalize();
     }
     this._cachedStatements.clear();
     this._log.debug("Discarded " + count + " cached statements.");
     return count;
   },
 
@@ -1165,17 +1165,16 @@ OpenedConnection.prototype = Object.free
   /**
    * The integer schema version of the database.
    *
    * This is 0 if not schema version has been set.
    *
    * @return Promise<int>
    */
   getSchemaVersion: function() {
-    let self = this;
     return this.execute("PRAGMA user_version").then(
       function onSuccess(result) {
         if (result == null) {
           return 0;
         }
         return JSON.stringify(result[0].getInt32(0));
       }
     );

--- a/toolkit/modules/Task.jsm
+++ b/toolkit/modules/Task.jsm
@@ -418,17 +418,16 @@ TaskImpl.prototype = {
 
       if (gMaintainStack &&
           aException._capturedTaskStack != this._stack &&
           typeof stack == "string") {
 
         // Rewrite the stack for more readability.
 
         let bottomStack = this._stack;
-        let topStack = stack;
 
         stack = Task.Debugging.generateReadableStack(stack);
 
         aException.stack = stack;
 
         // If aException is reinjected in the same task and rethrown,
         // we don't want to perform the rewrite again.
         aException._capturedTaskStack = bottomStack;

--- a/toolkit/modules/UpdateUtils.jsm
+++ b/toolkit/modules/UpdateUtils.jsm
@@ -319,33 +319,16 @@ XPCOMUtils.defineLazyGetter(UpdateUtils,
           {szCSDVersion: ctypes.ArrayType(WCHAR, SZCSDVERSIONLENGTH)},
           {wServicePackMajor: WORD},
           {wServicePackMinor: WORD},
           {wSuiteMask: WORD},
           {wProductType: BYTE},
           {wReserved: BYTE}
           ]);
 
-      // This structure is described at:
-      // http://msdn.microsoft.com/en-us/library/ms724958%28v=vs.85%29.aspx
-      const SYSTEM_INFO = new ctypes.StructType('SYSTEM_INFO',
-          [
-          {wProcessorArchitecture: WORD},
-          {wReserved: WORD},
-          {dwPageSize: DWORD},
-          {lpMinimumApplicationAddress: ctypes.voidptr_t},
-          {lpMaximumApplicationAddress: ctypes.voidptr_t},
-          {dwActiveProcessorMask: DWORD.ptr},
-          {dwNumberOfProcessors: DWORD},
-          {dwProcessorType: DWORD},
-          {dwAllocationGranularity: DWORD},
-          {wProcessorLevel: WORD},
-          {wProcessorRevision: WORD}
-          ]);
-
       let kernel32 = false;
       try {
         kernel32 = ctypes.open("Kernel32");
       } catch (e) {
         Cu.reportError("Unable to open kernel32! " + e);
         osVersion += ".unknown (unknown)";
       }
 

--- a/toolkit/modules/secondscreen/SimpleServiceDiscovery.jsm
+++ b/toolkit/modules/secondscreen/SimpleServiceDiscovery.jsm
@@ -164,17 +164,17 @@ var SimpleServiceDiscovery = {
     this._searchTimeout.initWithCallback(this._searchShutdown.bind(this), SSDP_DISCOVER_TIMEOUT, Ci.nsITimer.TYPE_ONE_SHOT);
 
     let data = SSDP_DISCOVER_PACKET;
 
     // Send discovery packets out at 1 per SSDP_TRANSMISSION_INTERVAL and send each SSDP_DISCOVER_ATTEMPTS times
     // to allow for packet loss on noisy networks.
     let timeout = SSDP_DISCOVER_DELAY;
     for (let attempts = 0; attempts < SSDP_DISCOVER_ATTEMPTS; attempts++) {
-      for (let [key, device] of this._devices) {
+      for (let [/* key */, device] of this._devices) {
         let target = device.target;
         setTimeout(function() {
           let msgData = data.replace("%SEARCH_TARGET%", target);
           try {
             let msgRaw = converter.convertToByteArray(msgData);
             socket.send(SSDP_ADDRESS, SSDP_PORT, msgRaw, msgRaw.length);
           } catch (e) {
             log("failed to convert to byte array: " + e);
@@ -219,17 +219,17 @@ var SimpleServiceDiscovery = {
   // Called when the search timeout is hit. We use it to cleanup the socket and
   // perform some post-processing on the services list.
   _searchShutdown: function _searchShutdown() {
     if (this._searchSocket) {
       // This will call onStopListening.
       this._searchSocket.close();
 
       // Clean out any stale services
-      for (let [key, service] of this._services) {
+      for (let [/* key */, service] of this._services) {
         if (service.lastPing != this._searchTimestamp) {
           this.removeService(service.uuid);
         }
       }
     }
 
     this._stopExternalDiscovery();
   },
@@ -300,29 +300,29 @@ var SimpleServiceDiscovery = {
       return this._services.get(aUUID);
     }
     return null;
   },
 
   // Returns an array copy of the active services
   get services() {
     let array = [];
-    for (let [key, service] of this._services) {
+    for (let [/* key */, service] of this._services) {
       let target = this._devices.get(service.deviceID);
       service.extensions = target.extensions;
       service.types = target.types;
       array.push(service);
     }
     return array;
   },
 
   // Returns false if the service does not match the device's filters
   _filterService: function _filterService(aService) {
     // Loop over all the devices, looking for one that matches the service
-    for (let [key, device] of this._devices) {
+    for (let [/* key */, device] of this._devices) {
       // First level of match is on the target itself
       if (device.target != aService.target) {
         continue;
       }
 
       // If we have no filter, everything passes
       if (!("filters" in device)) {
         aService.deviceID = device.id;

--- a/toolkit/modules/tests/browser/browser_RemotePageManager.js
+++ b/toolkit/modules/tests/browser/browser_RemotePageManager.js
@@ -95,17 +95,17 @@ add_task(function* init_navigate() {
   }
 
   yield loaded;
 
   gBrowser.goBack();
   port = yield waitForPort(TEST_URL, false);
 
   port.sendAsyncMessage("Ping2");
-  let message = yield waitForMessage(port, "Pong2");
+  yield waitForMessage(port, "Pong2");
   port.destroy();
 
   gBrowser.removeCurrentTab();
 });
 
 // Test that opening a page creates a port, sends the load event and then
 // closing the tab sends the unload event
 add_task(function* init_close() {

--- a/toolkit/modules/tests/xpcshell/test_CanonicalJSON.js
+++ b/toolkit/modules/tests/xpcshell/test_CanonicalJSON.js
@@ -64,17 +64,16 @@ add_task(function* test_canonicalJSON_do
 });
 
 
 add_task(function* test_canonicalJSON_preserves_data() {
   const records = [
     {'foo': 'bar', 'last_modified': '12345', 'id': '1'},
     {'bar': 'baz', 'last_modified': '45678', 'id': '2'},
   ]
-  const serialized = CanonicalJSON.stringify(records);
   const expected = '[{"foo":"bar","id":"1","last_modified":"12345"},' +
                    '{"bar":"baz","id":"2","last_modified":"45678"}]';
   do_check_eq(CanonicalJSON.stringify(records), expected);
 });
 
 add_task(function* test_canonicalJSON_does_not_add_space_separators() {
   const records = [
     {'foo': 'bar', 'last_modified': '12345', 'id': '1'},

--- a/toolkit/modules/tests/xpcshell/test_FileUtils.js
+++ b/toolkit/modules/tests/xpcshell/test_FileUtils.js
@@ -28,17 +28,17 @@ add_test(function test_getFile() {
   other.append("foobar");
   do_check_true(file.equals(other));
 
   run_next_test();
 });
 
 add_test(function test_getFile_nonexistentDir() {
   do_check_throws(function() {
-    let file = FileUtils.getFile("NonexistentD", ["foobar"]);
+    FileUtils.getFile("NonexistentD", ["foobar"]);
   }, Components.results.NS_ERROR_FAILURE);
 
   run_next_test();
 });
 
 add_test(function test_getFile_createDirs() {
   let file = FileUtils.getFile("ProfD", ["a", "b", "foobar"]);
   do_check_true(file instanceof Components.interfaces.nsIFile);
@@ -64,17 +64,17 @@ add_test(function test_getDir() {
   other.append("foodir");
   do_check_true(dir.equals(other));
 
   run_next_test();
 });
 
 add_test(function test_getDir_nonexistentDir() {
   do_check_throws(function() {
-    let file = FileUtils.getDir("NonexistentD", ["foodir"]);
+    FileUtils.getDir("NonexistentD", ["foodir"]);
   }, Components.results.NS_ERROR_FAILURE);
 
   run_next_test();
 });
 
 add_test(function test_getDir_shouldCreate() {
   let dir = FileUtils.getDir("ProfD", ["c", "d", "foodir"], true);
   do_check_true(dir instanceof Components.interfaces.nsIFile);

--- a/toolkit/modules/tests/xpcshell/test_GMPInstallManager.js
+++ b/toolkit/modules/tests/xpcshell/test_GMPInstallManager.js
@@ -544,23 +544,19 @@ add_task(function* test_simpleCheckAndIn
   let result = yield installManager.simpleCheckAndInstall();
   do_check_eq(result.status, "too-frequent-no-check");
 });
 
 /**
  * Tests that installing addons when there is no server works as expected
  */
 add_test(function test_installAddon_noServer() {
-  let dir = FileUtils.getDir("TmpD", [], true);
   let zipFileName = "test_GMP.zip";
   let zipURL = URL_HOST + ":0/" + zipFileName;
 
-  let data = "e~=0.5772156649";
-  let zipFile = createNewZipFile(zipFileName, data);
-
   let responseXML =
     "<?xml version=\"1.0\"?>" +
     "<updates>" +
     "    <addons>" +
     "        <addon id=\"gmp-gmpopenh264\"" +
     "               URL=\"" + zipURL + "\"" +
     "               hashFunction=\"sha256\"" +
     "               hashValue=\"11221cbda000347b054028b527a60e578f919cb10f322ef8077d3491c6fcb474\"" +

--- a/toolkit/modules/tests/xpcshell/test_Log.js
+++ b/toolkit/modules/tests/xpcshell/test_Log.js
@@ -52,17 +52,17 @@ add_task(function test_Logger() {
 });
 
 add_task(function test_Logger_parent() {
   // Check whether parenting is correct
   let grandparentLog = Log.repository.getLogger("grandparent");
   let childLog = Log.repository.getLogger("grandparent.parent.child");
   do_check_eq(childLog.parent.name, "grandparent");
 
-  let parentLog = Log.repository.getLogger("grandparent.parent");
+  Log.repository.getLogger("grandparent.parent");
   do_check_eq(childLog.parent.name, "grandparent.parent");
 
   // Check that appends are exactly in scope
   let gpAppender = new MockAppender(new Log.BasicFormatter());
   gpAppender.level = Log.Level.Info;
   grandparentLog.addAppender(gpAppender);
   childLog.info("child info test");
   Log.repository.rootLogger.info("this shouldn't show up in gpAppender");

--- a/toolkit/modules/tests/xpcshell/test_Promise.js
+++ b/toolkit/modules/tests/xpcshell/test_Promise.js
@@ -282,17 +282,17 @@ tests.push(
     let exception_content = new Error("Boom!");
 
     let observer_1 = source.promise.then(
       function onResolve() {
         exception_thrown = true;
         throw exception_content;
       });
 
-    let observer_2 = source.promise.then(
+    source.promise.then(
       function onResolve() {
         do_check_true(exception_thrown, "Second observer called after first observer has thrown");
       }
     );
 
     let result = observer_1.then(
       function onResolve() {
         do_throw("observer_1 should not have resolved");
@@ -955,17 +955,16 @@ tests.push(
 
 function wait_for_uncaught(aMustAppear, aTimeout = undefined) {
   let remaining = new Set();
   for (let k of aMustAppear) {
     remaining.add(k);
   }
   let deferred = Promise.defer();
   let print = do_print;
-  let execute_soon = do_execute_soon;
   let observer = function({message, stack}) {
     let data = message + stack;
     print("Observing " + message + ", looking for " + aMustAppear.join(", "));
     for (let expected of remaining) {
       if (data.indexOf(expected) != -1) {
         print("I found " + expected);
         remaining.delete(expected);
       }

--- a/toolkit/modules/tests/xpcshell/test_session_recorder.js
+++ b/toolkit/modules/tests/xpcshell/test_session_recorder.js
@@ -26,17 +26,17 @@ function monkeypatchStartupInfo(recorder
       };
     }
   });
 }
 
 function sleep(wait) {
   let deferred = Promise.defer();
 
-  let timer = CommonUtils.namedTimer(function onTimer() {
+  CommonUtils.namedTimer(function onTimer() {
     deferred.resolve();
   }, wait, deferred.promise, "_sleepTimer");
 
   return deferred.promise;
 }
 
 function getRecorder(name, start, offset) {
   let recorder = new SessionRecorder("testing." + name + ".");
@@ -298,9 +298,8 @@ add_task(function* test_record_activity(
   Services.obs.notifyObservers(null, "user-interaction-active", null);
   do_check_eq(recorder.activeTicks, 4);
 
   Services.obs.notifyObservers(null, "user-interaction-active", null);
   do_check_eq(recorder.activeTicks, 5);
 
   recorder.onShutdown();
 });
-

--- a/toolkit/modules/tests/xpcshell/test_sqlite.js
+++ b/toolkit/modules/tests/xpcshell/test_sqlite.js
@@ -489,17 +489,16 @@ add_task(function* test_shrink_memory() 
   yield c.shrinkMemory();
   yield c.close();
 });
 
 add_task(function* test_no_shrink_on_init() {
   let c = yield getConnection("no_shrink_on_init",
                               {shrinkMemoryOnConnectionIdleMS: 200});
 
-  let oldShrink = c._connectionData.shrinkMemory;
   let count = 0;
   Object.defineProperty(c._connectionData, "shrinkMemory", {
     value: function() {
       count++;
     },
   });
 
   // We should not shrink until a statement has been executed.
@@ -754,21 +753,21 @@ add_task(function* test_programmatic_bin
 
   // Add some data in an implicit transaction before beginning the batch insert.
   yield c.execute(sql, {id: 1, path: "works"});
 
   let secondSucceeded = false;
   try {
     yield c.executeTransaction(function* transaction() {
       // Insert one row. This won't implicitly start a transaction.
-      let result = yield c.execute(sql, bindings[0]);
+      yield c.execute(sql, bindings[0]);
 
       // Insert multiple rows. mozStorage will want to start a transaction.
       // One of the inserts will fail, so the transaction should be rolled back.
-      result = yield c.execute(sql, bindings);
+      yield c.execute(sql, bindings);
       secondSucceeded = true;
     });
   } catch (ex) {
     print("Caught expected exception: " + ex);
   }
 
   // We did not get to the end of our in-transaction block.
   do_check_false(secondSucceeded);
@@ -790,17 +789,17 @@ add_task(function* test_programmatic_bin
     {id: 2, path: "foobar"},
     {id: 1, path: "toofoo"},
   ];
 
   let sql = "INSERT INTO dirs VALUES (:id, :path)";
   let secondSucceeded = false;
   yield c.execute(sql, {id: 1, path: "works"});
   try {
-    let result = yield c.execute(sql, bindings);
+    yield c.execute(sql, bindings);
     secondSucceeded = true;
   } catch (ex) {
     print("Caught expected exception: " + ex);
   }
 
   do_check_false(secondSucceeded);
 
   // The entire batch failed.
@@ -913,17 +912,17 @@ add_task(function* test_cloneStorageConn
   yield c.asyncClose();
   yield clone2.close();
   yield clone.close();
 });
 
 // Test Sqlite.cloneStorageConnection invalid argument.
 add_task(function* test_cloneStorageConnection() {
   try {
-    let clone = yield Sqlite.cloneStorageConnection({ connection: null });
+    yield Sqlite.cloneStorageConnection({ connection: null });
     do_throw(new Error("Should throw on invalid connection"));
   } catch (ex) {
     if (ex.name != "TypeError") {
       throw ex;
     }
   }
 });
 

--- a/toolkit/modules/tests/xpcshell/test_timer.js
+++ b/toolkit/modules/tests/xpcshell/test_timer.js
@@ -39,17 +39,17 @@ add_task(function* test_setInterval() {
   do_check_true(interval1 > 0, "setTimeout returns a positive number");
 
   imported.clearInterval(interval1);
 
   const EXPECTED_CALLS = 5;
   let calls = 0;
 
   yield new Promise((resolve) => {
-    let interval2 = imported.setInterval((param1, param2) => {
+    imported.setInterval((param1, param2) => {
       do_check_true(true, "Should be called");
       do_check_eq(param1, 15, "first parameter is correct");
       do_check_eq(param2, "hola", "second parameter is correct");
       if (calls >= EXPECTED_CALLS) {
         resolve();
       }
       calls++;
     }, 100, 15, "hola");

--- a/toolkit/mozapps/extensions/test/xpcshell/test_syncGUID.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_syncGUID.js
@@ -147,9 +147,8 @@ add_test(function test_addon_manager_get
       AddonManager.getAddonBySyncGUID("DOES_NOT_EXIST", function(missing) {
         do_check_eq(undefined, missing);
 
         run_next_test();
       });
     });
   });
 });
-

--- a/toolkit/mozapps/extensions/test/xpcshell/test_webextension_icons.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_webextension_icons.js
@@ -159,9 +159,8 @@ add_task(function*() {
   equal(addon.icon64URL, null);
 
   equal(AddonManager.getPreferredIconURL(addon, 128), null);
 
   addon.uninstall();
 
   yield promiseRestartManager();
 });
-

--- a/toolkit/mozapps/update/nsUpdateService.js
+++ b/toolkit/mozapps/update/nsUpdateService.js
@@ -435,17 +435,17 @@ function getCanApplyUpdates() {
          * requires admin privileges to update other than Program Files.
          */
         let userCanElevate = false;
 
         if (parseFloat(windowsVersion) >= 6) {
           try {
             // KEY_UPDROOT will fail and throw an exception if
             // appDir is not under the Program Files, so we rely on that
-            let dir = Services.dirsvc.get(KEY_UPDROOT, Ci.nsIFile);
+            Services.dirsvc.get(KEY_UPDROOT, Ci.nsIFile);
             // appDir is under Program Files, so check if the user can elevate
             userCanElevate = Services.appinfo.QueryInterface(Ci.nsIWinAppHelper).
                              userCanElevate;
             LOG("getCanApplyUpdates - on Vista, userCanElevate: " + userCanElevate);
           }
           catch (ex) {
             // When the installation directory is not under Program Files,
             // fall through to checking if write access to the

--- a/toolkit/mozapps/update/tests/data/xpcshellUtilsAUS.js
+++ b/toolkit/mozapps/update/tests/data/xpcshellUtilsAUS.js
@@ -1321,17 +1321,17 @@ function getSpecialFolderDir(aCSIDL) {
                                            ctypes.winapi_abi,
                                            ctypes.bool, /* bool(return) */
                                            ctypes.int32_t, /* HWND hwndOwner */
                                            ctypes.char16_t.ptr, /* LPTSTR lpszPath */
                                            ctypes.int32_t, /* int csidl */
                                            ctypes.bool /* BOOL fCreate */);
 
   let aryPath = ctypes.char16_t.array()(260);
-  let rv = SHGetSpecialFolderPath(0, aryPath, aCSIDL, false);
+  SHGetSpecialFolderPath(0, aryPath, aCSIDL, false);
   lib.close();
 
   let path = aryPath.readString(); // Convert the c-string to js-string
   if (!path) {
     return null;
   }
   debugDump("SHGetSpecialFolderPath returned path: " + path);
   let dir = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsILocalFile);
@@ -4070,18 +4070,16 @@ function runUpdateUsingApp(aExpectedStat
       return;
     }
 
     do_execute_soon(runUpdateFinished);
   }
 
   debugDump("start - launching application to apply update");
 
-  let appBin = getApplyDirFile(DIR_MACOS + FILE_APP_BIN, false);
-
   let launchBin = getLaunchBin();
   let args = getProcessArgs();
   debugDump("launching " + launchBin.path + " " + args.join(" "));
 
   gProcess = Cc["@mozilla.org/process/util;1"].
              createInstance(Ci.nsIProcess);
   gProcess.init(launchBin);
 

--- a/toolkit/profile/content/profileSelection.js
+++ b/toolkit/profile/content/profileSelection.js
@@ -222,17 +222,16 @@ function RenameProfile()
     return true;
   }
 
   return false;
 }
 
 function ConfirmDelete()
 {
-  var deleteButton = document.getElementById("delbutton");
   var profileList = document.getElementById( "profiles" );
 
   var selectedItem = profileList.selectedItem;
   if (!selectedItem) {
     return false;
   }
 
   var selectedProfile = selectedItem.profile;