Implement WebBluetooth descriptor.readValue()

third_party/WebKit/LayoutTests/bluetooth/script-tests/descriptor/io-op-device-disconnects-before.js

+'use strict';
+promise_test(() => {
+  let val = new Uint8Array([1]);
+  return setBluetoothFakeAdapter('DisconnectingHealthThermometerAdapter')
+    .then(() => requestDeviceWithKeyDown({
+      filters: [{services: ['health_thermometer']}],
+      optionalServices: [request_disconnection_service_uuid]
+    }))
+    .then(device => device.gatt.connect())
+    .then(gattServer => {
+      let measurement_interval;
+      return gattServer.getPrimaryService('health_thermometer')
+        .then(ht=> ht.getCharacteristic('measurement_interval'))
+        .then(characteristic => characteristic.getDescriptor('gatt.characteristic_user_description'))
+        .then(d => user_description = d)
+        .then(() => get_request_disconnection(gattServer))
+        .then(requestDisconnection => requestDisconnection())
+        .then(() => assert_promise_rejects_with_message(
+          user_description.CALLS([
+            readValue()
+            ]),
+          new DOMException(
+            'GATT Server is disconnected. Cannot perform GATT operations.',
+            'NetworkError')));
+    });
+}, 'Device disconnects before FUNCTION_NAME. Reject with NetworkError.');