Always enable lazy sweeping.

Source/build/features.gypi

 #
 # Copyright (C) 2009 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 72 matching lines @@
           'WTF_USE_DEFAULT_RENDER_THEME=1',
         ],
       }],
       ['enable_oilpan==1', {
         'feature_defines': [
           'ENABLE_OILPAN=1',
           'ENABLE_LAZY_SWEEPING=1',
           'ENABLE_IDLE_GC=1',
         ],
       }],
+      ['enable_oilpan==0', {
+        'feature_defines': [
+          'ENABLE_LAZY_SWEEPING=1',
+        ],
+      }],
       ['blink_gc_profiling==1', {
         'feature_defines': [
           'ENABLE_GC_PROFILING=1',
         ],
       }],
       ['blink_logging_always_on==1', {
         'feature_defines': [
           'LOG_DISABLED=0',
         ],
       }],
       ['link_core_modules_separately==1', {
         'feature_defines': [
           'LINK_CORE_MODULES_SEPARATELY',
         ],
       }],
     ],
 
     # shared build only. If set to 1, link web, core and modules separately.
     'link_core_modules_separately%': '<(link_core_modules_separately)',
   },
 }