Fix product build

runtime/vm/isolate.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 1037 matching lines @@
   debugger_name_ = strdup(name);
 }
 
 
 bool Isolate::IsPaused() const {
   return (debugger_ != NULL) && (debugger_->PauseEvent() != NULL);
 }
 
 
 void Isolate::PausePostRequest() {
+  if (!FLAG_support_debugger) {
+    return;
+  }
   if (debugger_ == NULL) {
     return;
   }
   ASSERT(!IsPaused());
   const Error& error = Error::Handle(debugger_->PausePostRequest());
   if (!error.IsNull()) {
     Exceptions::PropagateError(error);
   }
 }
 
@@ skipping 1896 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart