Add parallel recompilation time to histogram and plot execution pause times.

src/counters.cc

Index: src/counters.cc
diff --git a/src/counters.cc b/src/counters.cc
index 811c0aa2e62038cc997a2fe1c0859b60fe02f7e2..db8a1237e958a4ca68fc08f6862d6c8bf3c9cb54 100644
--- a/src/counters.cc
+++ b/src/counters.cc
@@ -77,7 +77,7 @@ void* Histogram::CreateHistogram() const {
 
 // Start the timer.
 void HistogramTimer::Start() {
-  if (histogram_.Enabled()) {
+  if (histogram_.Enabled() || FLAG_log_timer_events) {
     stop_time_ = 0;
     start_time_ = OS::Ticks();
   }
@@ -87,11 +87,15 @@ void HistogramTimer::Start() {
 void HistogramTimer::Stop() {
   if (histogram_.Enabled()) {
     stop_time_ = OS::Ticks();
-
     // Compute the delta between start and stop, in milliseconds.
     int milliseconds = static_cast<int>(stop_time_ - start_time_) / 1000;
     histogram_.AddSample(milliseconds);
   }
+  if (FLAG_log_timer_events) {
+    stop_time_ = OS::Ticks();
+    Isolate::Current()->logger()->TimerEvent(
+        histogram_.name_, start_time_, stop_time_);
+  }
 }
 
 } }  // namespace v8::internal