Jankometer: Generalize the code more. Add better support for monitoring IO thread.

base/tracked.h

Index: base/tracked.h
diff --git a/base/tracked.h b/base/tracked.h
index b0be729a9d172eca0fc76e5d75c79720ca89c148..3622d1ca9e1bda65a3eb0819b245851b1d9c3841 100644
--- a/base/tracked.h
+++ b/base/tracked.h
@@ -107,8 +107,14 @@ class Tracked {
 
   bool MissingBirthplace() const;
 
+#if defined(TRACK_ALL_TASK_OBJECTS)
+  base::TimeTicks tracked_birth_time() const { return tracked_birth_time_; }
+#else
+  base::TimeTicks tracked_birth_time() const { return base::TimeTicks::Now(); }
+#endif  // defined(TRACK_ALL_TASK_OBJECTS)
+
  private:
-#ifdef TRACK_ALL_TASK_OBJECTS
+#if defined(TRACK_ALL_TASK_OBJECTS)
 
   // Pointer to instance were counts of objects with the same birth location
   // (on the same thread) are stored.
@@ -118,7 +124,7 @@ class Tracked {
   // reset before the object begins it active life.
   base::TimeTicks tracked_birth_time_;
 
-#endif  // TRACK_ALL_TASK_OBJECTS
+#endif  // defined(TRACK_ALL_TASK_OBJECTS)
 
   DISALLOW_COPY_AND_ASSIGN(Tracked);
 };