Implement WebBluetooth descriptor.readValue()

third_party/WebKit/LayoutTests/bluetooth/script-tests/descriptor/io-op-device-reconnects-during-success.js

+promise_test(() => {
+  let val = new Uint8Array([1]);
+  return setBluetoothFakeAdapter('DisconnectingDuringSuccessGATTOperationAdapter')
+    .then(() => requestDeviceWithKeyDown({
+      filters: [{services: ['health_thermometer']}]}))
+    .then(device => device.gatt.connect())
+    .then(gatt => gatt.getPrimaryService('health_thermometer'))
+    .then(service => service.getCharacteristic('measurement_interval'))
+    .then(characteristic => characteristic.getDescriptor('gatt.characteristic_user_description'))
+    .then(descriptor => {
+      let disconnected = eventPromise(descriptor.characteristic.service.device, 'gattserverdisconnected');
+      let promise = assert_promise_rejects_with_message(
+        descriptor.CALLS([
+          readValue()
+        ]),
+        new DOMException('GATT Server disconnected while performing a GATT operation.',
+                         'NetworkError'));
+      return disconnected.then(() => descriptor.characteristic.service.device.gatt.connect())
+        .then(() => promise);
+    });
+}, 'Device reconnects during a FUNCTION_NAME call that succeeds. Reject ' +
+   'with NetworkError.');