[heap] Implement concurrent marking boilerplate.

test/cctest/cctest.gyp

 # Copyright 2012 the V8 project authors. 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
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 86 matching lines @@
       'gay-precision.cc',
       'gay-precision.h',
       'gay-shortest.cc',
       'gay-shortest.h',
       'heap/heap-tester.h',
       'heap/heap-utils.cc',
       'heap/heap-utils.h',
       'heap/test-alloc.cc',
       'heap/test-array-buffer-tracker.cc',
       'heap/test-compaction.cc',
+      'heap/test-concurrent-marking.cc',
       'heap/test-heap.cc',
       'heap/test-incremental-marking.cc',
       'heap/test-lab.cc',
       'heap/test-mark-compact.cc',
       'heap/test-page-promotion.cc',
       'heap/test-spaces.cc',
       'libplatform/test-tracing.cc',
       'libsampler/test-sampler.cc',
       'parsing/test-parse-decision.cc',
       'parsing/test-preparser.cc',
@@ skipping 407 matching lines @@
             '../../gypfiles/isolate.gypi',
           ],
           'sources': [
             'cctest.isolate',
           ],
         },
       ],
     }],
   ],
 }