Revert "Fix runtime_call_stats for background parsing."

This reverts commit 8f4e8c0a.

Reason for revert: Speculative revert for http://crbug.com/717854

Original change's description:
> Fix runtime_call_stats for background parsing.
>
> BUG=v8:6093
>
> Change-Id: I365fbd7c3f33e2de47e0a84ee3ea631b4ffa6d35
> Reviewed-on: https://chromium-review.googlesource.com/488243
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
> Commit-Queue: Wiktor Garbacz <wiktorg@google.com>
> Cr-Commit-Position: refs/heads/master@{#45013}

TBR=marja@chromium.org
R=marja@chromium.org,vogelheim@chromium.org,cbruni@chromium.org,jochen@chromium.org
BUG=v8:6093,chromium:717854

Change-Id: Ia58a420ec4c1e84a9f01eb90545fabb0bc03aa63
Reviewed-on: https://chromium-review.googlesource.com/494568
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45070}

src/api.cc

@@ -2473,7 +2473,6 @@ MaybeLocal<Script> ScriptCompiler::Compile(Local<Context> context,
     source->parser->ReportErrors(isolate, script);
   }
   source->parser->UpdateStatistics(isolate, script);
-  source->info->UpdateStatisticsAfterBackgroundParse(isolate);
 
   i::DeferredHandleScope deferred_handle_scope(isolate);
   {

src/background-parsing-task.cc

@@ -37,9 +37,6 @@ BackgroundParsingTask::BackgroundParsingTask(
   info->set_unicode_cache(&source_->unicode_cache);
   info->set_compile_options(options);
   info->set_allow_lazy_parsing();
-  if (V8_UNLIKELY(FLAG_runtime_call_stats)) {
-    info->set_runtime_call_stats(new (info->zone()) RuntimeCallStats());
-  }
 
   source_->info->set_cached_data(&script_data_);
   // Parser needs to stay alive for finalizing the parsing on the main

src/compiler-dispatcher/compiler-dispatcher-job.cc

@@ -90,10 +90,6 @@ CompilerDispatcherJob::CompilerDispatcherJob(
   parse_info_->set_language_mode(language_mode);
   parse_info_->set_function_literal_id(function_literal_id);
   parse_info_->set_ast_string_constants(ast_string_constants);
-  if (V8_UNLIKELY(FLAG_runtime_call_stats)) {
-    parse_info_->set_runtime_call_stats(new (parse_info_->zone())
-                                            RuntimeCallStats());
-  }
 
   parse_info_->set_native(native);
   parse_info_->set_module(module);
@@ -270,10 +266,6 @@ void CompilerDispatcherJob::PrepareToParseOnMainThread() {
   parse_info_->set_unicode_cache(unicode_cache_.get());
   parse_info_->set_language_mode(shared_->language_mode());
   parse_info_->set_function_literal_id(shared_->function_literal_id());
-  if (V8_UNLIKELY(FLAG_runtime_call_stats)) {
-    parse_info_->set_runtime_call_stats(new (parse_info_->zone())
-                                            RuntimeCallStats());
-  }
 
   parser_.reset(new Parser(parse_info_.get()));
   MaybeHandle<ScopeInfo> outer_scope_info;
@@ -342,7 +334,6 @@ bool CompilerDispatcherJob::FinalizeParsingOnMainThread() {
     status_ = CompileJobStatus::kReadyToAnalyze;
   }
   parser_->UpdateStatistics(isolate_, script);
-  parse_info_->UpdateStatisticsAfterBackgroundParse(isolate_);
 
   DeferredHandleScope scope(isolate_);
   {

src/parsing/parse-info.cc

@@ -164,20 +164,6 @@ void ParseInfo::InitFromIsolate(Isolate* isolate) {
   set_ast_string_constants(isolate->ast_string_constants());
 }
 
-void ParseInfo::UpdateStatisticsAfterBackgroundParse(Isolate* isolate) {
-  // Copy over the counters from the background thread to the main counters on
-  // the isolate.
-  RuntimeCallStats* main_call_stats = isolate->counters()->runtime_call_stats();
-  if (FLAG_runtime_stats ==
-      v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE) {
-    DCHECK_NE(main_call_stats, runtime_call_stats());
-    DCHECK_NOT_NULL(main_call_stats);
-    DCHECK_NOT_NULL(runtime_call_stats());
-    main_call_stats->Add(runtime_call_stats());
-  }
-  set_runtime_call_stats(main_call_stats);
-}
-
 void ParseInfo::ParseFinished(std::unique_ptr<ParseInfo> info) {
   if (info->literal()) {
     base::LockGuard<base::Mutex> access_child_infos(&child_infos_mutex_);

src/parsing/parse-info.h

@@ -246,8 +246,6 @@ class V8_EXPORT_PRIVATE ParseInfo : public CompileJobFinishCallback {
     }
   }
 
-  void UpdateStatisticsAfterBackgroundParse(Isolate* isolate);
-
   // The key of the map is the FunctionLiteral's start_position
   std::map<int, ParseInfo*> child_infos() const;
 

src/parsing/parser.cc

@@ -3519,6 +3519,13 @@ void Parser::UpdateStatistics(Isolate* isolate, Handle<Script> script) {
   }
   isolate->counters()->total_preparse_skipped()->Increment(
       total_preparse_skipped_);
+  if (!parsing_on_main_thread_ &&
+      FLAG_runtime_stats ==
+          v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE) {
+    // Copy over the counters from the background thread to the main counters on
+    // the isolate.
+    isolate->counters()->runtime_call_stats()->Add(runtime_call_stats_);
+  }
 }
 
 void Parser::ParseOnBackground(ParseInfo* info) {
@@ -3535,6 +3542,10 @@ void Parser::ParseOnBackground(ParseInfo* info) {
       compile_options_ = ScriptCompiler::kNoCompileOptions;
     }
   }
+  if (FLAG_runtime_stats) {
+    // Create separate runtime stats for background parsing.
+    runtime_call_stats_ = new (zone()) RuntimeCallStats();
+  }
 
   std::unique_ptr<Utf16CharacterStream> stream;
   Utf16CharacterStream* stream_ptr;
@@ -5220,7 +5231,6 @@ void Parser::StitchAst(ParseInfo* top_level_parse_info, Isolate* isolate) {
     // If the parse task failed the function will be treated as lazy function
     // and reparsed before it gets called
     if (!result) continue;
-    result->UpdateStatisticsAfterBackgroundParse(isolate);
     if (!result->literal()) continue;
     while ((*it)->start_position() != child_info.first) {
       if (++it == literals_to_stitch_.end()) {