MD Downloads: use "big search" box like MD history

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar.html

 <link rel="import" href="chrome://resources/html/polymer.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/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_toolbar/cr_toolbar_search_field.html">
 
 <dom-module id="cr-toolbar">
   <template>
     <style>
       :host {
         --cr-toolbar-field-width: 580px;
         color: #fff;
         display: flex;
         height: 56px;
       }
 
       h1 {
-        @apply(--layout-flex);
         -webkit-margin-start: 6px;
+        flex: 1;
         font-size: 123%;
         font-weight: 400;
         text-overflow: ellipsis;
         overflow: hidden;
         white-space: nowrap;
       }
 
       #leftContent {
         -webkit-margin-start: 18px;
         align-items: center;
         display: flex;
         position: absolute;
         transition: opacity 100ms;
       }
 
       #menuButton {
         height: 32px;
         margin-bottom: 6px;
         margin-top: 6px;
         min-width: 32px;
         padding: 6px;
         width: 32px;
       }
 
-      :host(:not([show-menu])) #menuButton {
-        display: none;
-      }
-
       #centeredContent {
         -webkit-margin-start: var(--cr-toolbar-field-margin, 0);
-        -webkit-padding-end: 12px;
         display: flex;
         flex: 1 1 0;
         justify-content: center;
       }
 
+      :host([narrow_]) #centeredContent {
+        -webkit-padding-end: var(--cr-toolbar-field-end-padding, 12px);
+      }
+
+      :host(:not([narrow_])) h1 {
+        @apply(--cr-toolbar-header-wide);
+      }
+
       :host(:not([narrow_])) #leftContent {
         max-width: calc((100% - var(--cr-toolbar-field-width) - 18px) / 2);
+        @apply(--cr-toolbar-left-content-wide);
+      }
+
+      :host(:not([narrow_])) #rightContent {
+        @apply(--cr-toolbar-right-content-wide);
       }
 
       :host([narrow_]) #centeredContent {
         justify-content: flex-end;
       }
 
       :host([narrow_][showing-search_]) #leftContent {
         opacity: 0;
       }
     </style>
     <div id="leftContent">
-      <paper-icon-button id="menuButton" icon="cr:menu" on-tap="onMenuTap_"
-          title="[[menuLabel]]">
-      </paper-icon-button>
+      <template is="dom-if" if="[[showMenu]]">
+        <paper-icon-button id="menuButton" icon="cr:menu" on-tap="onMenuTap_"
+            title="[[menuLabel]]">
+        </paper-icon-button>
+      </template>
       <h1>[[pageName]]</h1>
     </div>
 
     <div id="centeredContent">
       <cr-toolbar-search-field id="search" narrow="[[narrow_]]"
           label="[[searchPrompt]]" clear-label="[[clearLabel]]"
           spinner-active="[[spinnerActive]]"
           showing-search="{{showingSearch_}}">
       </cr-toolbar-search-field>
       <iron-media-query query="(max-width: 900px)" query-matches="{{narrow_}}">
       </iron-media-query>
     </div>
+
+    <div id="rightContent">
+      <content select=".more-actions"></content>
+    </div>
   </template>
   <script src="cr_toolbar.js"></script>
 </dom-module>