Cleanup: removing unused descendants information from tracked objects

base/threading/worker_pool_posix.cc

 // Copyright (c) 2012 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/threading/worker_pool_posix.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 69 matching lines @@
   PlatformThread::SetName(name.c_str());
 
   for (;;) {
     PendingTask pending_task = pool_->WaitForTask();
     if (pending_task.task.is_null())
       break;
     TRACE_EVENT2("toplevel", "WorkerThread::ThreadMain::Run",
         "src_file", pending_task.posted_from.file_name(),
         "src_func", pending_task.posted_from.function_name());
 
-    tracked_objects::ThreadData::PrepareForStartOfRun(pending_task.birth_tally);
     tracked_objects::TaskStopwatch stopwatch;
     stopwatch.Start();
     pending_task.task.Run();
     stopwatch.Stop();
 
     tracked_objects::ThreadData::TallyRunOnWorkerThreadIfTracking(
         pending_task.birth_tally, pending_task.time_posted, stopwatch);
   }
 
   // The WorkerThread is non-joinable, so it deletes itself.
@@ skipping 84 matching lines @@
       return PendingTask(FROM_HERE, base::Closure());
     }
   }
 
   PendingTask pending_task = pending_tasks_.front();
   pending_tasks_.pop();
   return pending_task;
 }
 
 }  // namespace base