Track JS allocations as they arrive with no affection on performance when tracking is switched off

test/cctest/cctest.cc

Index: test/cctest/cctest.cc
diff --git a/test/cctest/cctest.cc b/test/cctest/cctest.cc
index b20696617cf7b171ca7604487f5407305d8613aa..215e4d76d5cf3e7ab62d6efa0086eac29819fc40 100644
--- a/test/cctest/cctest.cc
+++ b/test/cctest/cctest.cc
@@ -174,3 +174,9 @@ int main(int argc, char* argv[]) {
 
 RegisterThreadedTest *RegisterThreadedTest::first_ = NULL;
 int RegisterThreadedTest::count_ = 0;
+
+void RunAndTrackAllocations(void (*test)()) {
+  LocalContext env;
+  HeapObjectsTracker tracker;
+  (*test)();
+}