content: Add heartbeat trace for CategorizedWorkerPool.

base/synchronization/condition_variable_win.cc

Index: base/synchronization/condition_variable_win.cc
diff --git a/base/synchronization/condition_variable_win.cc b/base/synchronization/condition_variable_win.cc
index 61c6a715e0eccd8557338193f7f8313ab431b9ce..b701b5de0774f30db890a7a46a94fc5db2fa1635 100644
--- a/base/synchronization/condition_variable_win.cc
+++ b/base/synchronization/condition_variable_win.cc
@@ -26,8 +26,9 @@ void ConditionVariable::Wait() {
   TimedWait(TimeDelta::FromMilliseconds(INFINITE));
 }
 
-void ConditionVariable::TimedWait(const TimeDelta& max_time) {
+bool ConditionVariable::TimedWait(const TimeDelta& max_time) {
   base::ThreadRestrictions::AssertWaitAllowed();
+  bool timed_out = false;

[robliao, 2016/06/07 15:40:30]

Minimal scope: Move to right before the if check below.

   DWORD timeout = static_cast<DWORD>(max_time.InMilliseconds());
 
 #if DCHECK_IS_ON()
@@ -35,12 +36,15 @@ void ConditionVariable::TimedWait(const TimeDelta& max_time) {
 #endif
 
   if (FALSE == SleepConditionVariableSRW(&cv_, srwlock_, timeout, 0)) {
-    DCHECK(GetLastError() != WAIT_TIMEOUT);
+    timed_out = GetLastError() == WAIT_TIMEOUT;

[robliao, 2016/06/07 15:40:30]

Looks like your changelist uncovered a longstanding bug here. The comparison
should be GetLastError() == ERROR_TIMEOUT.

[prashant.n, 2016/06/07 15:49:54]

I just copied earlier code, I'll make chnages suggested by you.

+    DCHECK(max_time != TimeDelta::FromMilliseconds(INFINITE) || !timed_out);

[robliao, 2016/06/07 15:40:30]

This DCHECK will pass all cases where max_time is not set to infinite, missing
real failures where max_time is not INFINITE.

There's not a real need to check that we receive a timeout with INFINITE as its
specified by the Windows platform that INFINITE waits will not timeout.

As a result, the original DCHECK can still stand, and equivalently here
DCHECK(timed_out).

[prashant.n, 2016/06/07 15:49:54]

I'll correct this. May be I'll add two explicit dchecks with error messages.

   }
 
 #if DCHECK_IS_ON()
   user_lock_->CheckUnheldAndMark();
 #endif
+
+  return timed_out;
 }
 
 void ConditionVariable::Broadcast() {