Add bluetooth callbacks for fetching paired devices and stopping device discovery.

chrome/browser/resources/options2/advanced_options.js

Index: chrome/browser/resources/options2/advanced_options.js
diff --git a/chrome/browser/resources/options2/advanced_options.js b/chrome/browser/resources/options2/advanced_options.js
index 915ba53ced0f69d9e41462c4007b080df62a2901..a18ef0e00a3b1a7c3b69397f0ee23ae27b8ec571 100644
--- a/chrome/browser/resources/options2/advanced_options.js
+++ b/chrome/browser/resources/options2/advanced_options.js
@@ -429,6 +429,8 @@ cr.define('options', function() {
     if (!checked) {
       $('bluetooth-paired-devices-list').clear();
       $('bluetooth-unpaired-devices-list').clear();
+    } else {
+      chrome.send('getPairedBluetoothDevices');
     }
   }