Fix test maybe

src/layout/layout.js

@@ -16,6 +16,8 @@
  */
 (function() {
   'use strict';
+
+  var weakLayouts = new WeakSet()
   /**
    * Class constructor for Layout MDL component.
    * Implements MDL component design pattern defined at:
@@ -26,6 +28,7 @@
    */
   var MaterialLayout = function MaterialLayout(element) {
     this.element_ = element;
+    weakLayouts.add(this.element_)
 
     // Initialize instance.
     this.init();
@@ -141,7 +144,7 @@
 
   var mediaQuery = MaterialLayout.prototype.matchMedia_(
     /** @type {string} */ (MaterialLayout.prototype.Constant_.MAX_WIDTH));
-  mediaQuery.onchange = screenSizeHandler;
+  mediaQuery.onchange = MaterialLayout.prototype.screenSizeHandler_;
 
   MaterialLayout.prototype.screenSizeMediaQuery_ = mediaQuery;
 
@@ -196,12 +199,10 @@
    * @private
    */
 
-  function screenSizeHandler(e) {
+  MaterialLayout.prototype.screenSizeHandler_ = function (e) {
     // modified to query dependent elements rather than binding materialLayout to windows media query result
-    var materialLayouts = document.querySelectorAll('.mdl-layout');
-
-    for (var i = 0; i < materialLayouts.length; i++) {
-      var layout = materialLayouts[i];
+    for (var i = 0; i < weakLayouts.length; i++) {
+      var layout = weakLayouts[i];
 
       if (layout) {
         var drawerElement = layout.querySelector('.mdl-layout__drawer');
@@ -450,7 +451,7 @@
       // Keep an eye on screen size, and add/remove auxiliary class for styling
       // of small screens.
 
-      screenSizeHandler(this.screenSizeMediaQuery_);
+      this.screenSizeHandler_(this.screenSizeMediaQuery_);
 
       // Initialize tabs, if any.
       if (this.header_ && this.tabBar_) {