Don't create redundant ThreadData for Worker Threads

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 <stddef.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 62 matching lines @@
   scoped_refptr<base::PosixDynamicThreadPool> pool_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerThread);
 };
 
 void WorkerThread::ThreadMain() {
   g_worker_pool_running_on_this_thread.Get().Set(true);
   const std::string name = base::StringPrintf("%s/%d", name_prefix_.c_str(),
                                               PlatformThread::CurrentId());
   // Note |name.c_str()| must remain valid for for the whole life of the thread.
-  PlatformThread::SetName(name);
+  PlatformThread::SetName(name, true);

[jar (doing other things), 2016/04/20 04:34:51]

It is surprising to me that this is the *only* place where we SetName() for a
worker thread (in your CL).  What about Windows? Android? etc.?

Why don't the other platforms need this code?

[Zhenyu Shan, 2016/05/04 23:33:03]

Android shares posix WorkerThread::ThreadMain code.
Windows uses system managed worker pool implementation, see
worker_pool_win.cc:50 calling QueueUserWorkItem().

 
   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::TaskStopwatch stopwatch;
@@ skipping 93 matching lines @@
       return PendingTask(FROM_HERE, base::Closure());
     }
   }
 
   PendingTask pending_task = pending_tasks_.front();
   pending_tasks_.pop();
   return pending_task;
 }
 
 }  // namespace base