[turbofan] Add a mutex for recording compilation statistics

src/compilation-statistics.cc

Index: src/compilation-statistics.cc
diff --git a/src/compilation-statistics.cc b/src/compilation-statistics.cc
index d4ca39d6112a53ba2298d2fe626696d080cbf961..654807cc31c35419880177ef0edb093af732fc97 100644
--- a/src/compilation-statistics.cc
+++ b/src/compilation-statistics.cc
@@ -14,6 +14,8 @@ namespace internal {
 void CompilationStatistics::RecordPhaseStats(const char* phase_kind_name,
                                              const char* phase_name,
                                              const BasicStats& stats) {
+  base::LockGuard<base::Mutex> guard(&record_mutex_);
+
   std::string phase_name_str(phase_name);
   auto it = phase_map_.find(phase_name_str);
   if (it == phase_map_.end()) {
@@ -26,6 +28,8 @@ void CompilationStatistics::RecordPhaseStats(const char* phase_kind_name,
 
 void CompilationStatistics::RecordPhaseKindStats(const char* phase_kind_name,
                                                  const BasicStats& stats) {
+  base::LockGuard<base::Mutex> guard(&record_mutex_);
+
   std::string phase_kind_name_str(phase_kind_name);
   auto it = phase_kind_map_.find(phase_kind_name_str);
   if (it == phase_kind_map_.end()) {
@@ -39,6 +43,8 @@ void CompilationStatistics::RecordPhaseKindStats(const char* phase_kind_name,
 
 void CompilationStatistics::RecordTotalStats(size_t source_size,
                                              const BasicStats& stats) {
+  base::LockGuard<base::Mutex> guard(&record_mutex_);
+
   source_size += source_size;
   total_stats_.Accumulate(stats);
 }