Remove unneeded uses of logging.h in header files.

base/worker_pool_win.cc

 // Copyright (c) 2006-2008 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/worker_pool.h"
 
+#include "base/logging.h"
 #include "base/task.h"
 
 namespace {
 
 DWORD CALLBACK WorkItemCallback(void* param) {
   Task* task = static_cast<Task*>(param);
   task->Run();
   delete task;
   return 0;
 }
 
 }  // namespace
 
 bool WorkerPool::PostTask(const tracked_objects::Location& from_here,
                           Task* task, bool task_is_slow) {
   task->SetBirthPlace(from_here);
 
   ULONG flags = 0;
   if (task_is_slow)
     flags |= WT_EXECUTELONGFUNCTION;
 
   if (!QueueUserWorkItem(WorkItemCallback, task, flags)) {
     DLOG(ERROR) << "QueueUserWorkItem failed: " << GetLastError();
     delete task;
     return false;
   }
 
   return true;
 }