Move generate_perf_events_symbols flag to VM

runtime/vm/dart.h

Index: runtime/vm/dart.h
diff --git a/runtime/vm/dart.h b/runtime/vm/dart.h
index 80a085713679bde10dae6bd75610bceb53fc3162..a10ad266350bd217399d9ab9a58e6886d7f3c03b 100644
--- a/runtime/vm/dart.h
+++ b/runtime/vm/dart.h
@@ -34,13 +34,6 @@ class Dart : public AllStatic {
   static Isolate* vm_isolate() { return vm_isolate_; }
   static ThreadPool* thread_pool() { return thread_pool_; }
 
-  static void set_perf_events_file(void* file) {
-    perf_events_file_ = file;
-  }
-  static void* perf_events_file() {
-    return perf_events_file_;
-  }
-
   static void set_pprof_symbol_generator(DebugInfo* value) {
     pprof_symbol_generator_ = value;
   }
@@ -49,7 +42,6 @@ class Dart : public AllStatic {
  private:
   static Isolate* vm_isolate_;
   static ThreadPool* thread_pool_;
-  static void* perf_events_file_;
   static DebugInfo* pprof_symbol_generator_;
 };