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

chrome/browser/resources/md_history/history_toolbar.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-tabs/paper-tab.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-tabs/paper-tabs.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_toolbar/cr_toolbar.html">
 <link rel="import" href="chrome://history/icons.html">
 <link rel="import" href="chrome://history/shared_style.html">
@@ skipping 22 matching lines @@
       }
 
       #toolbar-container {
         height: var(--toolbar-height);
       }
 
       cr-toolbar {
         --cr-toolbar-field-margin: var(--side-bar-width);
       }
 
-      cr-toolbar[show-menu] {
+      :host([has-drawer]) cr-toolbar {
         --cr-toolbar-field-margin: 0;
       }
 
       :host(:not([has-drawer])) #overlay-wrapper {
         -webkit-margin-start: var(--side-bar-width);
       }
 
       #overlay-buttons {
         margin: 0 auto;
         max-width: var(--card-max-width);
@@ skipping 113 matching lines @@
               class="rtl-reversible"></paper-icon-button>
           <paper-icon-button icon="cr:chevron-right"
               alt="$i18n{rangeNext}" title="$i18n{rangeNext}"
               class="rtl-reversible"></paper-icon-button>
         </div>
       </div>
     </template>
   </template>
   <script src="chrome://history/history_toolbar.js"></script>
 </dom-module>