Use boolean instead of Atomic32 for is_profiling_ flag

src/cpu-profiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 473 matching lines @@
 
 void CpuProfiler::StartProcessorIfNotStarted() {
   if (processor_ == NULL) {
     Isolate* isolate = Isolate::Current();
 
     // Disable logging when using the new implementation.
     saved_logging_nesting_ = isolate->logger()->logging_nesting_;
     isolate->logger()->logging_nesting_ = 0;
     generator_ = new ProfileGenerator(profiles_);
     processor_ = new ProfilerEventsProcessor(generator_);
-    NoBarrier_Store(&is_profiling_, true);
+    is_profiling_ = true;
     processor_->Start();
     // Enumerate stuff we already have in the heap.
     if (isolate->heap()->HasBeenSetUp()) {
       if (!FLAG_prof_browser_mode) {
         bool saved_log_code_flag = FLAG_log_code;
         FLAG_log_code = true;
         isolate->logger()->LogCodeObjects();
         FLAG_log_code = saved_log_code_flag;
       }
       isolate->logger()->LogCompiledFunctions();
@@ skipping 40 matching lines @@
 
 
 void CpuProfiler::StopProcessor() {
   Logger* logger = Isolate::Current()->logger();
   Sampler* sampler = reinterpret_cast<Sampler*>(logger->ticker_);
   sampler->DecreaseProfilingDepth();
   if (need_to_stop_sampler_) {
     sampler->Stop();
     need_to_stop_sampler_ = false;
   }
-  NoBarrier_Store(&is_profiling_, false);
+  is_profiling_ = false;
   processor_->Stop();
   processor_->Join();
   delete processor_;
   delete generator_;
   processor_ = NULL;
   generator_ = NULL;
   logger->logging_nesting_ = saved_logging_nesting_;
 }
 
 
 void CpuProfiler::SetUp() {
   Isolate* isolate = Isolate::Current();
   if (isolate->cpu_profiler() == NULL) {
     isolate->set_cpu_profiler(new CpuProfiler());
   }
 }
 
 
 void CpuProfiler::TearDown() {
   Isolate* isolate = Isolate::Current();
   if (isolate->cpu_profiler() != NULL) {
     delete isolate->cpu_profiler();
   }
   isolate->set_cpu_profiler(NULL);
 }
 
 } }  // namespace v8::internal