src: ensure V8 initialized before marking milestone

PR-URL: #40405
Refs: electron/electron#31349
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

Author: codebytere

src/env.cc

@@ -458,8 +458,11 @@ void Environment::InitializeMainContext(Local<Context> context,
                            environment_start_time_);
   performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_NODE_START,
                            per_process::node_start_time);
-  performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_V8_START,
-                           performance::performance_v8_start);
+
+  if (per_process::v8_initialized) {
+    performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_V8_START,
+                            performance::performance_v8_start);
+  }
 }
 
 Environment::~Environment() {