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

chrome/browser/resources/md_history/app.vulcanized.html

Index: chrome/browser/resources/md_history/app.vulcanized.html
diff --git a/chrome/browser/resources/md_history/app.vulcanized.html b/chrome/browser/resources/md_history/app.vulcanized.html
index 5b7d2142a9047c42c37632980f57ea2deaf281ce..1c9edbb023cd868c1a9e0d6ddf1e4f4e108f7179 100644
--- a/chrome/browser/resources/md_history/app.vulcanized.html
+++ b/chrome/browser/resources/md_history/app.vulcanized.html
@@ -2795,9 +2795,10 @@ input[type='search']::-webkit-search-decoration, input[type='search']::-webkit-s
   <template>
     <style scope="cr-toolbar">:host {
   --cr-toolbar-field-width: 580px;
+        --cr-toolbar-height: 56px;
         color: #fff;
         display: flex;
-        height: 56px;
+        height: var(--cr-toolbar-height);
 }
 
 h1 {
@@ -2859,11 +2860,67 @@ h1 {
   opacity: 0;
 }
 
+#menuPromo {
+  -webkit-padding-end: 12px;
+        -webkit-padding-start: 8px;
+        align-items: center;
+        background: #616161;
+        border-radius: 2px;
+        color: white;
+        display: flex;
+        font-size: 92.3%;
+        font-weight: 500;
+        opacity: 0;
+        padding-bottom: 6px;
+        padding-top: 6px;
+        position: absolute;
+        top: var(--cr-toolbar-height);
+        white-space: nowrap;
+        z-index: 2;
+}
+
+#menuPromo::before {
+  background: inherit;
+        
+        clip-path: polygon(0 105%, 100% 105%, 50% 0);  
+        content: '';
+        display: block;
+        left: 10px;
+        height: 6px;
+        position: absolute;
+        top: -6px;
+        width: 12px;
+}
+
+:host-context([dir=rtl]) #menuPromo::before {
+  left: auto;
+        right: 10px;
+}
+
+#closePromo {
+  -webkit-appearance: none;
+        -webkit-margin-start: 12px;
+        background: none;
+        border: none;
+        color: inherit;
+        font-size: 20px;  
+        line-height: 20px;
+        padding: 0;
+        width: 20px;
+}
+
 </style>
     <div id="leftContent">
-      <template is="dom-if" if="[[showMenu]]">
-        <paper-icon-button id="menuButton" icon="cr:menu" on-tap="onMenuTap_" title="[[menuLabel]]">
+      
+      <template is="dom-if" if="[[showMenu]]" restamp="">
+        <paper-icon-button id="menuButton" icon="cr:menu" on-tap="onMenuTap_" title="[[titleIfNotShowMenuPromo_(menuLabel, showMenuPromo)]]" aria-label$="[[menuLabel]]">
         </paper-icon-button>
+        <template is="dom-if" if="[[showMenuPromo]]">
+          <div id="menuPromo" role="tooltip">
+            [[menuPromo]]
+            <button id="closePromo" on-tap="onClosePromoTap_" aria-label$="[[closeMenuPromo]]">✕</button>
+          
+        </div></template>
       </template>
       <h1>[[pageName]]</h1>
     </div>
@@ -2880,6 +2937,7 @@ h1 {
     </div>
   </template>
   </dom-module>
+<link rel="import" href="chrome://history/constants.html">
 <iron-iconset-svg size="24" name="history">
   <svg>
     <defs>
@@ -3219,7 +3277,7 @@ paper-tabs {
 
 </style>
     <div id="toolbar-container">
-      <cr-toolbar id="main-toolbar" page-name="$i18n{title}" clear-label="$i18n{clearSearch}" search-prompt="$i18n{searchPrompt}" hidden$="[[itemsSelected_]]" spinner-active="[[spinnerActive]]" show-menu="[[hasDrawer]]" menu-label="$i18n{historyMenuButton}" on-search-changed="onSearchChanged_">
+      <cr-toolbar id="main-toolbar" page-name="$i18n{title}" clear-label="$i18n{clearSearch}" search-prompt="$i18n{searchPrompt}" hidden$="[[itemsSelected_]]" spinner-active="[[spinnerActive]]" show-menu="[[hasDrawer]]" show-menu-promo="[[showMenuPromo_]]" menu-label="$i18n{historyMenuButton}" menu-promo="$i18n{menuPromo}" close-menu-promo="$i18n{closeMenuPromo}" on-search-changed="onSearchChanged_" on-cr-menu-promo-shown="onMenuPromoShown_">
         <div class="more-actions">
           <template is="dom-if" if="[[showSyncNotice]]">
             <button is="paper-icon-button-light" id="info-button" on-tap="onInfoButtonTap_" aria-label="$i18n{hasSyncedResultsDescription}">
@@ -3588,7 +3646,6 @@ paper-tabs {
   </template>
 
   </dom-module>
-<link rel="import" href="chrome://history/constants.html">
 <dom-module id="iron-collapse" assetpath="chrome://resources/polymer/v1_0/iron-collapse/" css-build="shadow">
 
   <template>