content: Add heartbeat trace for CategorizedWorkerPool.

base/synchronization/condition_variable_posix.cc

Index: base/synchronization/condition_variable_posix.cc
diff --git a/base/synchronization/condition_variable_posix.cc b/base/synchronization/condition_variable_posix.cc
index d86fd180ec7f3056dbf22cf0997826b04d7fdde3..a023d37fa832bfe4498346437a6f4d3f3b59f16e 100644
--- a/base/synchronization/condition_variable_posix.cc
+++ b/base/synchronization/condition_variable_posix.cc
@@ -73,7 +73,7 @@ void ConditionVariable::Wait() {
 #endif
 }
 
-void ConditionVariable::TimedWait(const TimeDelta& max_time) {
+bool ConditionVariable::TimedWait(const TimeDelta& max_time) {
   base::ThreadRestrictions::AssertWaitAllowed();
   int64_t usecs = max_time.InMicroseconds();
   struct timespec relative_time;
@@ -119,9 +119,13 @@ void ConditionVariable::TimedWait(const TimeDelta& max_time) {
 #endif  // OS_MACOSX
 
   DCHECK(rv == 0 || rv == ETIMEDOUT);
+
 #if DCHECK_IS_ON()
   user_lock_->CheckUnheldAndMark();
 #endif
+
+  // Return true if timeout occurred.
+  return rv == ETIMEDOUT;
 }
 
 void ConditionVariable::Broadcast() {