Revert 107895 - Fully enable about:tracking by default

base/threading/worker_pool_posix.h

Index: base/threading/worker_pool_posix.h
===================================================================
--- base/threading/worker_pool_posix.h	(revision 107960)
+++ base/threading/worker_pool_posix.h	(working copy)
@@ -53,11 +53,13 @@
                 const base::Closure& task);
     ~PendingTask();
 
+#if defined(TRACK_ALL_TASK_OBJECTS)
     // Counter for location where the Closure was posted from.
-    tracked_objects::Births* birth_tally;
+    tracked_objects::Births* post_births;
 
     // Time the task was posted.
-    tracked_objects::TrackedTime time_posted;
+    TimeTicks time_posted;
+#endif  // defined(TRACK_ALL_TASK_OBJECTS)
 
     const tracked_objects::Location posted_from;