Make PendingTask move-only and pass it by value on retaining params

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 132 matching lines @@
     const base::Closure& task) {
   PendingTask pending_task(from_here, task);
   AddTask(&pending_task);
 }
 
 void PosixDynamicThreadPool::AddTask(PendingTask* pending_task) {
   AutoLock locked(lock_);
   DCHECK(!terminated_)
       << "This thread pool is already terminated.  Do not post new tasks.";
 
-  pending_tasks_.push(*pending_task);
-  pending_task->task.Reset();
+  pending_tasks_.push(std::move(*pending_task));
 
   // We have enough worker threads.
   if (static_cast<size_t>(num_idle_threads_) >= pending_tasks_.size()) {
     pending_tasks_available_cv_.Signal();
   } else {
     // The new PlatformThread will take ownership of the WorkerThread object,
     // which will delete itself on exit.
     WorkerThread* worker = new WorkerThread(name_prefix_, this);
     PlatformThread::CreateNonJoinable(0, worker);
   }
@@ skipping 14 matching lines @@
     num_idle_threads_--;
     if (num_idle_threads_cv_.get())
       num_idle_threads_cv_->Signal();
     if (pending_tasks_.empty()) {
       // We waited for work, but there's still no work.  Return NULL to signal
       // the thread to terminate.
       return PendingTask(FROM_HERE, base::Closure());
     }
   }
 
-  PendingTask pending_task = pending_tasks_.front();
+  PendingTask pending_task = std::move(pending_tasks_.front());
   pending_tasks_.pop();
   return pending_task;
 }
 
 }  // namespace base