MD downloads: add a narrow mode for smaller windows

chrome/browser/resources/md_downloads/toolbar.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('downloads', function() {
   var Toolbar = Polymer({
     is: 'downloads-toolbar',
 
     /** @param {!downloads.ActionService} actionService */
     setActionService: function(actionService) {
@@ skipping 66 matching lines @@
       if (this.showingSearch_) {
         this.$['search-term'].focus();
       } else {
         this.$['search-term'].value = '';
         this.onSearchTermInput_();
       }
     },
 
     /** @private */
     updateClearAll_: function() {
-      this.$['clear-all'].hidden = !this.canClearAll();
+      this.$$('#actions .clear-all').hidden = !this.canClearAll();
+      this.$$('paper-menu .clear-all').hidden = !this.canClearAll();
     },
   });
 
   return {Toolbar: Toolbar};
 });
+
+// TODO(dbeam): https://github.com/PolymerElements/iron-dropdown/pull/16/files
+/** @suppress {checkTypes} */
+(function() {
+Polymer.IronDropdownScrollManager.pushScrollLock = function() {};
+})();