Implement WebBluetooth getDescriptor[s]

third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-invalid-name.js

+'use strict';
+promise_test(() => {
+  let promise;
+  return setBluetoothFakeAdapter('DisconnectingHealthThermometerAdapter')
+    .then(() => requestDeviceWithKeyDown({
+      filters: [{services: ['health_thermometer']}]}))
+    .then(device => device.gatt.connect())
+    .then(gattServer => gattServer.getPrimaryService('health_thermometer'))
+    .then(service => service.getCharacteristic('measurement_interval'))
+    .then(characteristic => {
+      return assert_promise_rejects_with_message(
+        characteristic.CALLS([
+          getDescriptor('invalid-name')|
+          getDescriptors('invalid-name')]),
+          new DOMException(
+              'Failed to execute \'FUNCTION_NAME\' on ' +
+                  '\'BluetoothRemoteGATTCharacteristic\': Invalid Descriptor name: ' +
+                  '\'invalid-name\'. ' +
+                  'It must be a valid UUID alias (e.g. 0x1234), ' +
+                  'UUID (lowercase hex characters e.g. ' +
+                  '\'00001234-0000-1000-8000-00805f9b34fb\'), ' +
+                  'or recognized standard name from ' +
+                  'https://developer.bluetooth.org/gatt/descriptors/' +
+                  'Pages/DescriptorsHomePage.aspx' +
+                  ' e.g. \'gatt.characteristic_presentation_format\'.',
+              'TypeError'));
+
+    })
+}, 'Test to ensure FUNCTION_NAME throws when called with an invalid name.');