[MD settings][cros accounts] Updates the accounts page according to the specs

chrome/browser/resources/settings/people_page/users_page.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="/controls/settings_checkbox.html">
 <link rel="import" href="/settings_shared_css.html">
 <link rel="import" href="user_list.html">
 <link rel="import" href="users_add_user_dialog.html">
 
 <dom-module id="settings-users-page">
   <template>
     <style include="settings-shared">
       .users {
         /* The users box must line up with the checkbox text. */
         -webkit-margin-start: 36px;
       }
+
+      .settings-box:first-of-type {
+        border-top: none;
+      }
+
+      #add-user-button {
+        /* Add user button must be lined up with the start of users' names. */
+        -webkit-margin-start: 56px;
+      }
     </style>
-    <div class="settings-box"
-        hidden$="[[isOwnerLabelHidden_(isOwner_, isWhitelistManaged_)]]">
-      $i18n{usersModifiedByOwnerLabel}
-    </div>
-    <div class="settings-box" hidden$="[[!isWhitelistManaged_]]">
-      $i18n{settingsManagedLabel}
-    </div>
+    <template is="dom-if" if="[[isWhitelistManaged_]]">
+      <div class="settings-box">$i18n{settingsManagedLabel}</div>
+    </template>
+    <template is="dom-if" if="[[!isWhitelistManaged_]]">
+      <template is="dom-if" if="[[!isOwner_]]">
+        <div class="settings-box">$i18n{usersModifiedByOwnerLabel}</div>
+      </template>
+    </template>
     <div class="settings-box block">
       <settings-checkbox
           pref="{{prefs.cros.accounts.allowBWSI}}"
           label="$i18n{guestBrowsingLabel}"
           disabled="[[isEditingDisabled_(isOwner_, isWhitelistManaged_)]]">
       </settings-checkbox>
       <settings-checkbox
           pref="{{prefs.cros.accounts.supervisedUsersEnabled}}"
           label="$i18n{supervisedUsersLabel}"
           disabled="[[isEditingDisabled_(isOwner_, isWhitelistManaged_)]]">
       </settings-checkbox>
       <settings-checkbox
           pref="{{prefs.cros.accounts.showUserNamesOnSignIn}}"
           label="$i18n{showOnSigninLabel}"
           disabled="[[isEditingDisabled_(isOwner_, isWhitelistManaged_)]]">
       </settings-checkbox>
       <settings-checkbox
           pref="{{prefs.cros.accounts.allowGuest}}"
           id="restrictSignIn"
           label="$i18n{restrictSigninLabel}"
           disabled="[[isEditingDisabled_(isOwner_, isWhitelistManaged_)]]"
           inverted>
       </settings-checkbox>
       <div class="users">
         <settings-user-list prefs="[[prefs]]"
-            disabled="[[isEditingUsersDisabled_(isOwner_, isWhitelistManaged_, prefs.cros.accounts.allowGuest.value)]]">
+            disabled="[[isEditingUsersDisabled_(isOwner_, isWhitelistManaged_,
+                prefs.cros.accounts.allowGuest.value)]]">
         </settings-user-list>
-        <paper-button on-tap="openAddUserDialog_"
-            disabled="[[isEditingUsersDisabled_(isOwner_, isWhitelistManaged_, prefs.cros.accounts.allowGuest.value)]]">
+        <div id="add-user-button" class="list-item list-button"
+            on-tap="openAddUserDialog_"
+            hidden="[[isEditingUsersDisabled_(isOwner_, isWhitelistManaged_,
+                prefs.cros.accounts.allowGuest.value)]]">
           $i18n{addUsers}
-        </paper-button>
+        </div>
       </div>
     </div>
     <settings-users-add-user-dialog id="addUserDialog">
     </settings-users-add-user-dialog>
   </template>
   <script src="users_page.js"></script>
 </dom-module>