Add new flag to trace-wrappables bot

scripts/slave/recipe_modules/chromium_tests/chromium_fyi.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from . import steps
 
 RESULTS_URL = 'https://chromeperf.appspot.com'
 
 
 KITCHEN_TEST_SPEC = {
@@ skipping 159 matching lines @@
         'BUILD_CONFIG': 'Debug',
         'TARGET_BITS': 64,
       },
       'compile_targets': [
         'blink_tests',
       ],
       'tests': [
         steps.BlinkTest(extra_args=[
           '--additional-driver-flag',
           '--enable-blink-features=TraceWrappables',
+          '--additional-driver-flag',
+          '--js-flags=--incremental-marking-wrappers',
         ]),
       ],
       'testing': {
         'platform': 'linux',
       },
       'enable_swarming': True,
       'use_isolate': True,
     },
     'WebKit Mac - WPTServe':{
       'chromium_config': 'chromium',
@@ skipping 1905 matching lines @@
         'TARGET_PLATFORM': 'win',
         'TARGET_BITS': 32,
       },
       'bot_type': 'builder_tester',
       'testing': { 'platform': 'win', },
       'use_isolate': True,
       'enable_swarming': True,
     },
   },
 }