Cleanup: removing unused descendants information from tracked objects

base/debug/task_annotator.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/task_annotator.h"
 
 #include "base/debug/alias.h"
 #include "base/pending_task.h"
 #include "base/trace_event/trace_event.h"
 #include "base/tracked_objects.h"
@@ skipping 10 matching lines @@
 void TaskAnnotator::DidQueueTask(const char* queue_function,
                                  const PendingTask& pending_task) {
   TRACE_EVENT_FLOW_BEGIN0(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"),
                           queue_function,
                           TRACE_ID_MANGLE(GetTaskTraceID(pending_task)));
 }
 
 void TaskAnnotator::RunTask(const char* queue_function,
                             const char* run_function,
                             const PendingTask& pending_task) {
-  tracked_objects::ThreadData::PrepareForStartOfRun(pending_task.birth_tally);
   tracked_objects::TaskStopwatch stopwatch;
   stopwatch.Start();
   tracked_objects::Duration queue_duration =
       stopwatch.StartTime() - pending_task.EffectiveTimePosted();
 
   TRACE_EVENT_FLOW_END1(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"),
                         queue_function,
                         TRACE_ID_MANGLE(GetTaskTraceID(pending_task)),
                         "queue_duration",
                         queue_duration.InMilliseconds());
@@ skipping 25 matching lines @@
       pending_task, stopwatch);
 }
 
 uint64 TaskAnnotator::GetTaskTraceID(const PendingTask& task) const {
   return (static_cast<uint64>(task.sequence_num) << 32) |
          ((static_cast<uint64>(reinterpret_cast<intptr_t>(this)) << 32) >> 32);
 }
 
 }  // namespace debug
 }  // namespace base