cros: Use runtime stylus detection for ash palette.

chrome/browser/resources/settings/device_page/device_page.html

 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="device_page_browser_proxy.html">
 <link rel="import" href="display.html">
 <link rel="import" href="keyboard.html">
@@ skipping 20 matching lines @@
             [[getPointersTitle_(hasMouse_, hasTouchpad_)]]
           </div>
           <button class="subpage-arrow" is="paper-icon-button-light"></button>
         </div>
         <div id="keyboardRow" class="settings-box" on-tap="onKeyboardTap_"
             actionable>
           <iron-icon icon="settings:keyboard"></iron-icon>
           <div class="middle">$i18n{keyboardTitle}</div>
           <button class="subpage-arrow" is="paper-icon-button-light"></button>
         </div>
-        <template is="dom-if" if="[[stylusAllowed_]]">
+        <template is="dom-if" if="[[hasStylus_]]">
           <div id="stylusRow" class="settings-box" on-tap="onStylusTap_"
               actionable>
             <iron-icon icon="settings:note"></iron-icon>
             <div class="middle">$i18n{stylusTitle}</div>
           <button class="subpage-arrow" is="paper-icon-button-light"></button>
           </div>
         </template>
         <div id="displayRow" class="settings-box" on-tap="onDisplayTap_"
             actionable>
           <iron-icon icon="settings:desktop-windows"></iron-icon>
@@ skipping 45 matching lines @@
           </settings-pointers>
         </settings-subpage>
       </template>
       <template is="dom-if" route-path="/keyboard-overlay">
         <settings-subpage
             associated-control="[[$$('#keyboardRow')]]"
             page-title="$i18n{keyboardTitle}">
           <settings-keyboard prefs="{{prefs}}"></settings-keyboard>
         </settings-subpage>
       </template>
-      <template is="dom-if" if="[[stylusAllowed_]]">
-        <template is="dom-if" route-path="/stylus">
-          <settings-subpage
-              associated-control="[[$$('#stylusRow')]]"
-              page-title="$i18n{stylusTitle}">
-            <settings-stylus prefs="{{prefs}}"></settings-stylus>
-          </settings-subpage>
-        </template>
+      <template is="dom-if" route-path="/stylus">
+        <settings-subpage
+            associated-control="[[$$('#stylusRow')]]"
+            page-title="$i18n{stylusTitle}">
+          <settings-stylus prefs="{{prefs}}"></settings-stylus>
+        </settings-subpage>
       </template>
       <template is="dom-if" route-path="/display">
         <settings-subpage
             associated-control="[[$$('#displayRow')]]"
             page-title="$i18n{displayTitle}">
           <settings-display></settings-display>
         </settings-subpage>
       </template>
       <template is="dom-if" route-path="/storage">
         <settings-subpage
             associated-control="[[$$('#storageRow')]]"
             page-title="$i18n{storageTitle}">
           <settings-storage></settings-storage>
         </settings-subpage>
       </template>
     </settings-animated-pages>
   </template>
   <script src="device_page.js"></script>
 </dom-module>