cros: Use runtime stylus detection for ash palette.

chrome/browser/resources/settings/device_page/device_page.js

Index: chrome/browser/resources/settings/device_page/device_page.js
diff --git a/chrome/browser/resources/settings/device_page/device_page.js b/chrome/browser/resources/settings/device_page/device_page.js
index b3bb4acc65d12446faed1485211b399f86723921..23a004e28425926d8d7456fa57df93f2841254ca 100644
--- a/chrome/browser/resources/settings/device_page/device_page.js
+++ b/chrome/browser/resources/settings/device_page/device_page.js
@@ -22,22 +22,25 @@ Polymer({
     },
 
     /**
-     * |hasMouse_| and |hasTouchpad_| start undefined so observers don't trigger
-     * until both have been populated.
+     * |hasMouse_|, |hasTouchpad_|, and |hasStylus_| start undefined so
+     * observers don't trigger until they have been populated.
      * @private
      */
-    hasMouse_: Boolean,
+    hasMouse_: {
+      type: Boolean,
+      value: false
+    },
 
     /** @private */
-    hasTouchpad_: Boolean,
+    hasTouchpad_: {
+      type: Boolean,
+      value: false
+    },
 
     /** @private */
-    stylusAllowed_: {
+    hasStylus_: {
       type: Boolean,
-      value: function() {
-        return loadTimeData.getBoolean('stylusAllowed');
-      },
-      readOnly: true,
+      value: false
     },
 
     /**
@@ -109,6 +112,10 @@ Polymer({
         'has-touchpad-changed', this.set.bind(this, 'hasTouchpad_'));
     settings.DevicePageBrowserProxyImpl.getInstance().initializePointers();
 
+    this.addWebUIListener(
+        'has-stylus-changed', this.set.bind(this, 'hasStylus_'));
+    settings.DevicePageBrowserProxyImpl.getInstance().initializeStylus();
+
     if (this.enablePowerSettings_) {
       this.addWebUIListener(
           'battery-status-changed', this.set.bind(this, 'batteryStatus_'));