MD History: hide tooltip promo when drawer is swiped open

chrome/browser/resources/md_history/app.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/cr/ui.html">
 <link rel="import" href="chrome://resources/html/cr/ui/command.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-media-query/iron-media-query.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-pages/iron-pages.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-scroll-target-behavior/iron-scroll-target-behavior.html">
 <link rel="import" href="chrome://history/history_toolbar.html">
 <link rel="import" href="chrome://history/list_container.html">
 <link rel="import" href="chrome://history/router.html">
 <link rel="import" href="chrome://history/shared_style.html">
 <link rel="import" href="chrome://history/side_bar.html">
 <link rel="stylesheet" href="chrome://resources/css/md_colors.css">
 
 <!-- Lazy loaded: history-synced-device-manager, app-drawer. -->
 
 <dom-module id="history-app">
   <template>
     <style include="shared-style">
       :host {
         display: block;
         height: 100%;
         overflow: hidden;
+        z-index: 0;
       }
 
       history-toolbar {
         background: var(--md-toolbar-color);
+        z-index: 2;
       }
 
       /* Sizing this with flex causes slow load performance, see
        * crbug.com/618153. TODO(dbeam): is this still an issue? */
       #main-container {
         height: calc(100% - var(--toolbar-height));
         position: relative;
+        z-index: 1;
       }
 
       :host([grouped_]) #main-container {
         height: calc(100% - var(--toolbar-grouped-height));
       }
 
       #content-side-bar {
         float: left;
       }
 
       :host-context([dir='rtl']) #content-side-bar {
         float: right;
       }
 
       #content,
       #content > * {
         height: 100%;
       }
 
       #drawer:unresolved {
         display: none;
       }
 
+      #drawer {
+        z-index: 3;
+      }
+
       #drawer-header {
         align-items: center;
         border-bottom: 1px solid rgba(0, 0, 0, 0.08);
         box-sizing: border-box;
         display: flex;
         height: var(--toolbar-height);
       }
 
       h1 {
         -webkit-padding-start: 24px;
@@ skipping 24 matching lines @@
     <history-toolbar id="toolbar"
         spinner-active="[[shouldShowSpinner_(queryState_.querying,
                                              queryState_.incremental,
                                              queryState_.searchTerm)]]"
         is-grouped-mode="{{grouped_}}"
         grouped-range="{{queryState_.range}}"
         search-term="{{queryState_.searchTerm}}"
         query-start-time="[[queryResult_.info.queryStartTime]]"
         query-end-time="[[queryResult_.info.queryEndTime]]"
         has-drawer="[[hasDrawer_]]"
-        show-sync-notice="[[showSyncNotice_(hasSyncedResults, selectedPage_)]]">
+        show-sync-notice="[[showSyncNotice_(hasSyncedResults, selectedPage_)]]"
+        show-menu-promo="[[showMenuPromo_]]">
     </history-toolbar>
 
     <div id="main-container">
       <history-side-bar id="content-side-bar" selected-page="{{selectedPage_}}"
           show-footer="[[showSidebarFooter]]"
           hidden$="[[hasDrawer_]]">
       </history-side-bar>
       <iron-pages id="content" attr-for-selected="path"
           fallback-selection="history"
           selected="[[getSelectedPage_(selectedPage_, items)]]"
@@ skipping 24 matching lines @@
         </history-side-bar>
       </app-drawer>
     </template>
 
     <iron-media-query query="(max-width: 1023px)"
         query-matches="{{hasDrawer_}}">
     </iron-media-query>
   </template>
   <script src="chrome://history/app.js"></script>
 </dom-module>