Always initialize the debugger eagerly.

src/isolate-inl.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ISOLATE_INL_H_
 #define V8_ISOLATE_INL_H_
 
 #include "debug.h"
 #include "isolate.h"
 #include "utils/random-number-generator.h"
@@ skipping 13 matching lines @@
   c_entry_fp_ = isolate->c_entry_fp(isolate->thread_local_top());
 }
 
 
 bool Isolate::IsCodePreAgingActive() {
   return FLAG_optimize_for_size && FLAG_age_code && !IsDebuggerActive();
 }
 
 
 bool Isolate::IsDebuggerActive() {
-  if (!NoBarrier_Load(&debugger_initialized_)) return false;
   return debugger()->IsDebuggerActive();
 }
 
 
 bool Isolate::DebuggerHasBreakPoints() {
   return debug()->has_break_points();
 }
 
 
 RandomNumberGenerator* Isolate::random_number_generator() {
   if (random_number_generator_ == NULL) {
     random_number_generator_ = new RandomNumberGenerator;
   }
   return random_number_generator_;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_INL_H_