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

src/serialize.h

Index: src/serialize.h
diff --git a/src/serialize.h b/src/serialize.h
index 563f0a06d025fb247d987beb357a0bea6212f447..8e1e1a4ddcbfcbeb4889c4fe698214c360539daf 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -366,6 +366,10 @@ class Deserializer: public SerializerDeserializer {
   Address Allocate(int space_index, int size) {
     Address address = high_water_[space_index];
     high_water_[space_index] = address + size;
+    HeapProfiler* profiler = isolate_->heap_profiler();
+    if (profiler->is_tracking_allocations()) {
+      profiler->NewObjectEvent(address, size);
+    }
     return address;
   }