Expose counters in javascript.

src/d8.cc

 // 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 1193 matching lines @@
     fprintf(stderr, "bzip error code: %d\n", bz2_result);
     Exit(1);
   }
 #endif
 
 #ifndef V8_SHARED
   Shell::counter_map_ = new CounterMap();
   // Set up counters
   if (i::StrLength(i::FLAG_map_counters) != 0)
     MapCounters(i::FLAG_map_counters);
-  if (i::FLAG_dump_counters) {
+  if (i::FLAG_dump_counters || i::FLAG_track_gc_object_stats) {
     V8::SetCounterFunction(LookupCounter);
     V8::SetCreateHistogramFunction(CreateHistogram);
     V8::SetAddHistogramSampleFunction(AddHistogramSample);
   }
 #endif  // V8_SHARED
   if (options.test_shell) return;
 
 #ifndef V8_SHARED
   Locker lock;
   HandleScope scope;
@@ skipping 668 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif