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

base/sequenced_task_runner.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.
 
 #ifndef BASE_SEQUENCED_TASK_RUNNER_H_
 #define BASE_SEQUENCED_TASK_RUNNER_H_
 
 #include "base/base_export.h"
+#include "base/callback.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "base/task_runner.h"
 
 namespace base {
 
 // A SequencedTaskRunner is a subclass of TaskRunner that provides
 // additional guarantees on the order that tasks are started, as well
 // as guarantees on when tasks are in sequence, i.e. one task finishes
 // before the other one starts.
 //
@@ skipping 83 matching lines @@
   // A simple corollary is that posting a task as non-nestable can
   // only delay when the task gets run.  That is, posting a task as
   // non-nestable may not affect when the task gets run, or it could
   // make it run later than it normally would, but it won't make it
   // run earlier than it normally would.
 
   // TODO(akalin): Get rid of the boolean return value for the methods
   // below.
 
   bool PostNonNestableTask(const tracked_objects::Location& from_here,
-                           const Closure& task);
+                           Closure task);
 
   virtual bool PostNonNestableDelayedTask(
       const tracked_objects::Location& from_here,
-      const Closure& task,
+      Closure task,
       base::TimeDelta delay) = 0;
 
   // Submits a non-nestable task to delete the given object.  Returns
   // true if the object may be deleted at some point in the future,
   // and false if the object definitely will not be deleted.
   template <class T>
   bool DeleteSoon(const tracked_objects::Location& from_here,
                   const T* object) {
     return DeleteOrReleaseSoonInternal(from_here, &DeleteHelper<T>::DoDelete,
                                        object);
@@ skipping 30 matching lines @@
     if (ptr)
       task_runner_->DeleteSoon(FROM_HERE, ptr);
   }
 
   scoped_refptr<SequencedTaskRunner> task_runner_;
 };
 
 }  // namespace base
 
 #endif  // BASE_SEQUENCED_TASK_RUNNER_H_