Fix WebBluetooth generator to distinguish between different methods.

third_party/WebKit/LayoutTests/bluetooth/script-tests/gatt-op-garbage-collection-ran-during-error.js

-'use strict';
-promise_test(() => {
-  let val = new Uint8Array([1]);
-  let promise;
-  return setBluetoothFakeAdapter('FailingGATTOperationsAdapter')
-    .then(() => requestDeviceWithKeyDown({
-      filters: [{services: [errorUUID(0xA0)]}]}))
-    .then(device => device.gatt.connect())
-    .then(gattServer => gattServer.getPrimaryService(errorUUID(0xA0)))
-    .then(service => service.getCharacteristic(errorUUID(0xA1)))
-    .then(error_characteristic => {
-      promise = assert_promise_rejects_with_message(
-        error_characteristic.CALLS([
-          readValue()|
-          writeValue(val)|
-          startNotifications()]),
-        new DOMException(
-          'GATT Server disconnected while performing a GATT operation.',
-          'NetworkError'));
-      // Disconnect called to clear attributeInstanceMap and allow the
-      // object to get garbage collected.
-      error_characteristic.service.device.gatt.disconnect();
-    })
-    .then(runGarbageCollection)
-    .then(() => promise);
-}, 'Garbage Collection ran during a FUNCTION_NAME call that fails. ' +
-   'Should not crash.');