Use OnceClosure in TestPendingTask

base/test/test_pending_task.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_TEST_TEST_PENDING_TASK_H_
 #define BASE_TEST_TEST_PENDING_TASK_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event_argument.h"
 
 namespace base {
 
 // TestPendingTask is a helper class for test TaskRunner
 // implementations.  See test_simple_task_runner.h for example usage.
 
 struct TestPendingTask {
   enum TestNestability { NESTABLE, NON_NESTABLE };
 
   TestPendingTask();
-  TestPendingTask(const TestPendingTask& other);
+  TestPendingTask(TestPendingTask&& other);
   TestPendingTask(const tracked_objects::Location& location,
                   const Closure& task,
                   TimeTicks post_time,
                   TimeDelta delay,
                   TestNestability nestability);
   ~TestPendingTask();
 
+  TestPendingTask& operator=(TestPendingTask&& other);
+
   // Returns post_time + delay.
   TimeTicks GetTimeToRun() const;
 
   // Returns true if this task is nestable and |other| isn't, or if
   // this task's time to run is strictly earlier than |other|'s time
   // to run.
   //
   // Note that two tasks may both have the same nestability and delay.
   // In that case, the caller must use some other criterion (probably
   // the position in some queue) to break the tie.  Conveniently, the
   // following STL functions already do so:
   //
   //   - std::min_element
   //   - std::stable_sort
   //
   // but the following STL functions don't:
   //
   //   - std::max_element
   //   - std::sort.
   bool ShouldRunBefore(const TestPendingTask& other) const;
 
   tracked_objects::Location location;
-  Closure task;
+  OnceClosure task;
   TimeTicks post_time;
   TimeDelta delay;
   TestNestability nestability;
 
   // Functions for using test pending task with tracing, useful in unit
   // testing.
   void AsValueInto(base::trace_event::TracedValue* state) const;
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> AsValue() const;
   std::string ToString() const;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestPendingTask);
 };
 
 // gtest helpers which allow pretty printing of the tasks, very useful in unit
 // testing.
 std::ostream& operator<<(std::ostream& os, const TestPendingTask& task);
 void PrintTo(const TestPendingTask& task, std::ostream* os);
 
 }  // namespace base
 
 #endif  // BASE_TEST_TEST_PENDING_TASK_H_