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

chrome/browser/resources/md_history/history_toolbar.js

Index: chrome/browser/resources/md_history/history_toolbar.js
diff --git a/chrome/browser/resources/md_history/history_toolbar.js b/chrome/browser/resources/md_history/history_toolbar.js
index d346317e913f5fc1cb10b098c0b94610f010e0a4..b55066ede237a75802bc995008cbe1a6124dc642 100644
--- a/chrome/browser/resources/md_history/history_toolbar.js
+++ b/chrome/browser/resources/md_history/history_toolbar.js
@@ -61,6 +61,15 @@ Polymer({
 
     // The end time of the query range.
     queryEndTime: String,
+
+    // Whether to show the menu promo (a tooltip that points at the menu button
+    // in narrow mode).
+    showMenuPromo_: {
+      type: Boolean,
+      value: function() {
+        return loadTimeData.getBoolean('showMenuPromo');
+      },
+    },
   },
 
   /**
@@ -88,6 +97,11 @@ Polymer({
     searchField.setValue(search);
   },
 
+  /** @private */
+  onMenuPromoShown_: function() {
+    md_history.BrowserService.getInstance().menuPromoShown();
+  },
+
   /**
    * @param {!CustomEvent} event
    * @private