Reland of "Create rtc::AtomicInt POD struct."

webrtc/system_wrappers/source/trace_impl.cc

Index: webrtc/system_wrappers/source/trace_impl.cc
diff --git a/webrtc/system_wrappers/source/trace_impl.cc b/webrtc/system_wrappers/source/trace_impl.cc
index 5029f5ab6ea7267d82d6220928de0b77d9a24e92..3bf1f1bb64b07476725df8a8731cd68f9af34ce8 100644
--- a/webrtc/system_wrappers/source/trace_impl.cc
+++ b/webrtc/system_wrappers/source/trace_impl.cc
@@ -34,7 +34,7 @@ namespace webrtc {
 const int Trace::kBoilerplateLength = 71;
 const int Trace::kTimestampPosition = 13;
 const int Trace::kTimestampLength = 12;
-volatile int Trace::level_filter_ = kTraceDefault;
+rtc::AtomicInt Trace::level_filter_ = {kTraceDefault};
 
 // Construct On First Use idiom. Avoids "static initialization order fiasco".
 TraceImpl* TraceImpl::StaticInstance(CountOperation count_operation,
@@ -548,12 +548,12 @@ int32_t Trace::TraceFile(char file_name[FileWrapper::kMaxFileNameSize]) {
 
 // static
 void Trace::set_level_filter(int filter) {
-  rtc::AtomicOps::ReleaseStore(&level_filter_, filter);
+  rtc::AtomicInt::ReleaseStore(&level_filter_, filter);
 }
 
 // static
 int Trace::level_filter() {
-  return rtc::AtomicOps::AcquireLoad(&level_filter_);
+  return rtc::AtomicInt::AcquireLoad(&level_filter_);
 }
 
 // static