Fix data race in v8::internal::UnboundQueue

src/cpu-profiler.cc

Index: src/cpu-profiler.cc
diff --git a/src/cpu-profiler.cc b/src/cpu-profiler.cc
index 42722191bd5a0cce0c9bdb7d8a909cbd3d30fb2a..109ddd5d976f0a36ccdb1512e02b2a78467238d6 100644
--- a/src/cpu-profiler.cc
+++ b/src/cpu-profiler.cc
@@ -191,9 +191,8 @@ void ProfilerEventsProcessor::AddCurrentStack() {
 
 
 bool ProfilerEventsProcessor::ProcessCodeEvent(unsigned* dequeue_order) {
-  if (!events_buffer_.IsEmpty()) {
-    CodeEventsContainer record;
-    events_buffer_.Dequeue(&record);
+  CodeEventsContainer record;
+  if (events_buffer_.Dequeue(&record)) {
     switch (record.generic.type) {
 #define PROFILER_TYPE_CASE(type, clss)                          \
       case CodeEventRecord::type:                               \