Add queued_time_ms trace for events in message loop

base/tracking_info.h

Index: base/tracking_info.h
diff --git a/base/tracking_info.h b/base/tracking_info.h
index dacbcea1d2b9d83a4734b5c5b21216f4cac004f7..ba9585e6d9b7d6a8105a9c427d121d038c388b8f 100644
--- a/base/tracking_info.h
+++ b/base/tracking_info.h
@@ -11,6 +11,7 @@
 #ifndef BASE_TRACKING_INFO_H_
 #define BASE_TRACKING_INFO_H_
 
+#include "base/profiler/tracked_time.h"
 #include "base/time/time.h"
 
 namespace tracked_objects {
@@ -27,6 +28,17 @@ struct BASE_EXPORT TrackingInfo {
                base::TimeTicks delayed_run_time);
   ~TrackingInfo();
 
+  // To avoid conflating our stats with the delay duration in a PostDelayedTask,
+  // we identify such tasks, and replace their post_time with the time they
+  // were scheduled (requested?) to emerge from the delayed task queue. This
+  // means that queuing delay for such tasks will show how long they went
+  // unserviced, after they *could* be serviced.  This is the same stat as we
+  // have for non-delayed tasks, and we consistently call it queuing delay.
+  tracked_objects::TrackedTime EffectiveTimePosted() const {
+    return tracked_objects::TrackedTime(
+        delayed_run_time.is_null() ? time_posted : delayed_run_time);
+  }
+
   // Record of location and thread that the task came from.
   tracked_objects::Births* birth_tally;