[MD Extensions] Add a details subpage, move to one list

chrome/browser/resources/md_extensions/sidebar.html

 <link rel="import" href="chrome://resources/html/cr.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-checkbox/paper-checkbox.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-item/paper-item.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-menu.html">
 <link rel="import" href="chrome://extensions/icons.html">
 
 <dom-module id="extensions-sidebar">
   <template>
-    <paper-menu id="section-menu">
+    <paper-menu id="section-menu" selected="0">
       <paper-item class="section-menu-item" id="sections-extensions"
-          on-tap="onExtensionsTap_" hidden$="[[hideExtensionsButton]]">
+          on-tap="onExtensionsTap_">
         <iron-icon icon="extension"></iron-icon>
         <span i18n-content="sidebarExtensions"></span>
       </paper-item>
       <paper-item class="section-menu-item" id="sections-apps"
-          on-tap="onAppsTap_" hidden$="[[hideAppsButton]]">
+          on-tap="onAppsTap_">
         <iron-icon icon="apps"></iron-icon>
         <span i18n-content="sidebarApps"></span>
       </paper-item>
-      <paper-item class="section-menu-item" id="sections-websites"
-          on-tap="onWebsitesTap_" hidden$="[[hideWebsitesButton]]">
-        <iron-icon icon="cloud"></iron-icon>
-        <span i18n-content="sidebarWebsites"></span>
-      </paper-item>
     </paper-menu>
     <div id="devtools-container">
       <paper-item id="developer-mode">
         <span i18n-content="developerMode"></span>
         <paper-checkbox id="developer-mode-checkbox"
             checked="[[inDevMode]]"
             on-change="onDevModeChange_"></paper-checkbox>
       </paper-item>
       <template is="dom-if" if="[[inDevMode]]">
         <div id="devtools-controls">
@@ skipping 16 matching lines @@
       </template>
     </div>
     <paper-item id="more-extensions" i18n-content="getMoreExtensions">
     </paper-item>
     <paper-item id="keyboard-shortcuts" i18n-content="keyboardShortcuts">
     </paper-item>
   </template>
   <link rel="import" type="css" href="chrome://extensions/sidebar.css">
   <script src="chrome://extensions/sidebar.js"></script>
 </dom-module>