MD History: promote menu button to show clear browsing data in narrow mode

chrome/browser/resources/md_downloads/crisper.js

 // Copyright (c) 2013 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.
 function assert(condition, opt_message) {
   if (!condition) {
     var message = 'Assertion failed';
     if (opt_message) message = message + ': ' + opt_message;
     var error = new Error(message);
     var global = function() {
       return this;
@@ skipping 6744 matching lines @@
 // Copyright 2016 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.
 Polymer({
   is: 'cr-toolbar',
   properties: {
     pageName: String,
     searchPrompt: String,
     clearLabel: String,
     menuLabel: String,
+    menuPromo: String,
     spinnerActive: Boolean,
     showMenu: {
       type: Boolean,
       value: false
     },
+    showMenuPromo: {
+      type: Boolean,
+      value: false
+    },
+    closeMenuPromo: String,
     narrow_: {
       type: Boolean,
       reflectToAttribute: true
     },
     showingSearch_: {
       type: Boolean,
       reflectToAttribute: true
     }
   },
+  observers: [ 'possiblyShowMenuPromo_(showMenu, showMenuPromo, showingSearch_)' ],
   getSearchField: function() {
     return this.$.search;
   },
-  onMenuTap_: function(e) {
+  onClosePromoTap_: function() {
+    this.showMenuPromo = false;
+  },
+  onMenuTap_: function() {
     this.fire('cr-menu-tap');
+    this.onClosePromoTap_();
+  },
+  possiblyShowMenuPromo_: function() {
+    Polymer.RenderStatus.afterNextRender(this, function() {
+      if (this.showMenu && this.showMenuPromo && !this.showingSearch_) {
+        this.$$('#menuPromo').animate({
+          opacity: [ 0, .9 ]
+        }, {
+          duration: 500,
+          fill: 'forwards'
+        });
+      }
+    }.bind(this));
+  },
+  titleIfNotShowMenuPromo_: function(title, showMenuPromo) {
+    return showMenuPromo ? '' : title;
   }
 });
 
 // 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',
     properties: {
@@ skipping 190 matching lines @@
   };
   return {
     Manager: Manager
   };
 });
 
 // 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.
 window.addEventListener('load', downloads.Manager.onLoad);