503     if (instance_ == NULL) {  in AddActiveSampler()
506       instance_ = new SamplerThread(sampler->interval());  in AddActiveSampler()
511     DCHECK(!instance_->active_samplers_.Contains(sampler));  in AddActiveSampler()
512     DCHECK(instance_->interval_ == sampler->interval());  in AddActiveSampler()
513     instance_->active_samplers_.Add(sampler);  in AddActiveSampler()
515     if (need_to_start) instance_->StartSynchronously();  in AddActiveSampler()
524       bool removed = instance_->active_samplers_.RemoveElement(sampler);  in RemoveActiveSampler()
530       if (instance_->active_samplers_.is_empty()) {  in RemoveActiveSampler()
531         instance_to_remove = instance_;  in RemoveActiveSampler()
532         instance_ = NULL;  in RemoveActiveSampler()
563   static SamplerThread* instance_;  member in v8::internal::SamplerThread
573 SamplerThread* SamplerThread::instance_ = NULL;  member in v8::internal::SamplerThread