Refactor the ring buffer in GCTracer.

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
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@@ skipping 125 matching lines @@
         'test-diy-fp.cc',
         'test-double.cc',
         'test-dtoa.cc',
         'test-elements-kind.cc',
         'test-fast-dtoa.cc',
         'test-feedback-vector.cc',
         'test-field-type-tracking.cc',
         'test-fixed-dtoa.cc',
         'test-flags.cc',
         'test-func-name-inference.cc',
-        'test-gc-tracer.cc',
         'test-global-handles.cc',
         'test-global-object.cc',
         'test-hashing.cc',
         'test-hashmap.cc',
         'test-heap-profiler.cc',
         'test-hydrogen-types.cc',
         'test-identity-map.cc',
         'test-inobject-slack-tracking.cc',
         'test-list.cc',
         'test-liveedit.cc',
@@ skipping 262 matching lines @@
             '../../build/isolate.gypi',
           ],
           'sources': [
             'cctest.isolate',
           ],
         },
       ],
     }],
   ],
 }