[counters] Use separate counters for background parsing

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index f4687eb3f7739019495be2e68eda80f0b5a875aa..db35d201bf0d2d10433a7c4c925ec70062bf51d3 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -838,11 +838,14 @@ class PreParser : public ParserBase<PreParser> {
     kPreParseSuccess
   };
 
-  PreParser(Zone* zone, Scanner* scanner, AstValueFactory* ast_value_factory,
+  PreParser(Zone* zone, Scanner* scanner, uintptr_t stack_limit,
+            AstValueFactory* ast_value_factory,
             PendingCompilationErrorHandler* pending_error_handler,
-            RuntimeCallStats* runtime_call_stats, uintptr_t stack_limit)
+            RuntimeCallStats* runtime_call_stats,
+            bool parsing_on_main_thread = true)
       : ParserBase<PreParser>(zone, scanner, stack_limit, nullptr,
-                              ast_value_factory, runtime_call_stats),
+                              ast_value_factory, runtime_call_stats,
+                              parsing_on_main_thread),
         use_counts_(nullptr),
         track_unresolved_variables_(false),
         pending_error_handler_(pending_error_handler) {}