cros: Use runtime stylus detection for ash palette.

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

Index: chrome/browser/resources/settings/device_page/device_page.html
diff --git a/chrome/browser/resources/settings/device_page/device_page.html b/chrome/browser/resources/settings/device_page/device_page.html
index e50598a7eecbdb9f4c45d2cf04af28595b168d99..12c9659084917df28e5ccaf110bf2b80fb3877ab 100644
--- a/chrome/browser/resources/settings/device_page/device_page.html
+++ b/chrome/browser/resources/settings/device_page/device_page.html
@@ -38,7 +38,7 @@
           <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>
@@ -104,14 +104,12 @@
           <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="[[$$('#stylusRow')]]"
-              page-title="$i18n{stylusTitle}">
-            <settings-stylus prefs="{{prefs}}"></settings-stylus>
-          </settings-subpage>
-        </template>
+      <template is="dom-if" route-path="/stylus" if="[[hasStylus_]]">
+        <settings-subpage
+            associated-control="[[$$('#stylusRow')]]"
+            page-title="$i18n{stylusTitle}">
+          <settings-stylus prefs="{{prefs}}"></settings-stylus>
+        </settings-subpage>
       </template>
       <template is="dom-if" route-path="/display">
         <settings-subpage