Pass Callback to TaskRunner by value and consume it on invocation (1)

base/threading/worker_pool_posix.h

 // 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.
 //
 // The thread pool used in the POSIX implementation of WorkerPool dynamically
 // adds threads as necessary to handle all tasks.  It keeps old threads around
 // for a period of time to allow them to be reused.  After this waiting period,
 // the threads exit.  This thread pool uses non-joinable threads, therefore
 // worker threads are not joined during process shutdown.  This means that
 // potentially long running tasks (such as DNS lookup) do not block process
@@ skipping 10 matching lines @@
 // implementation of WorkerPool.  No one else should be using these classes.
 // These symbols are exported in a header purely for testing purposes.
 
 #ifndef BASE_THREADING_WORKER_POOL_POSIX_H_
 #define BASE_THREADING_WORKER_POOL_POSIX_H_
 
 #include <memory>
 #include <queue>
 #include <string>
 
-#include "base/callback_forward.h"
+#include "base/callback.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/pending_task.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
 #include "base/tracked_objects.h"
 
 namespace base {
 
 class BASE_EXPORT PosixDynamicThreadPool
     : public RefCountedThreadSafe<PosixDynamicThreadPool> {
  public:
   class PosixDynamicThreadPoolPeer;
 
   // All worker threads will share the same |name_prefix|.  They will exit after
   // |idle_seconds_before_exit|.
   PosixDynamicThreadPool(const std::string& name_prefix,
                          int idle_seconds_before_exit);
 
   // Adds |task| to the thread pool.
-  void PostTask(const tracked_objects::Location& from_here,
-                const Closure& task);
+  void PostTask(const tracked_objects::Location& from_here, Closure task);
 
   // Worker thread method to wait for up to |idle_seconds_before_exit| for more
   // work from the thread pool.  Returns NULL if no work is available.
   PendingTask WaitForTask();
 
  private:
   friend class RefCountedThreadSafe<PosixDynamicThreadPool>;
   friend class PosixDynamicThreadPoolPeer;
 
   ~PosixDynamicThreadPool();
@@ skipping 16 matching lines @@
   // Only used for tests to ensure correct thread ordering.  It will always be
   // NULL in non-test code.
   std::unique_ptr<ConditionVariable> num_idle_threads_cv_;
 
   DISALLOW_COPY_AND_ASSIGN(PosixDynamicThreadPool);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_WORKER_POOL_POSIX_H_