bluetooth: Add characteristic list to DeviceDetailsPage in internals page.

chrome/browser/resources/bluetooth_internals/device_details_page.js

Index: chrome/browser/resources/bluetooth_internals/device_details_page.js
diff --git a/chrome/browser/resources/bluetooth_internals/device_details_page.js b/chrome/browser/resources/bluetooth_internals/device_details_page.js
index 6112bf011f7e995996efe0ce5fe0e1aa178dee14..fb1dda58c017b545e6fd37acf88f6ec4e7a7da3c 100644
--- a/chrome/browser/resources/bluetooth_internals/device_details_page.js
+++ b/chrome/browser/resources/bluetooth_internals/device_details_page.js
@@ -83,6 +83,20 @@ cr.define('device_details_page', function() {
       this.devicePtr !== null ? this.disconnect() : this.connect();
     }.bind(this));
 
+    this.serviceList.addEventListener(
+        'characteristicsrequested', function(event) {
+          if (!this.devicePtr) {
+            event.target.onCharacteristicsRequested([]);
+            return;
+          }
+
+          this.devicePtr.getCharacteristics(event.detail.serviceId).then(
+              function(response) {
+                event.target.onCharacteristicsRequested(
+                    response.characteristics);
+              }.bind(this));
+        }.bind(this));
+
     this.redraw();
   }