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

base/test/test_mock_time_task_runner.cc

 // Copyright 2015 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/test/test_mock_time_task_runner.h"
 
+#include <utility>
+
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/clock.h"
 #include "base/time/tick_clock.h"
 
 namespace base {
 
@@ skipping 55 matching lines @@
 
 // TestMockTimeTaskRunner::TestOrderedPendingTask -----------------------------
 
 // Subclass of TestPendingTask which has a strictly monotonically increasing ID
 // for every task, so that tasks posted with the same 'time to run' can be run
 // in the order of being posted.
 struct TestMockTimeTaskRunner::TestOrderedPendingTask
     : public base::TestPendingTask {
   TestOrderedPendingTask();
   TestOrderedPendingTask(const tracked_objects::Location& location,
-                         const Closure& task,
+                         Closure task,
                          TimeTicks post_time,
                          TimeDelta delay,
                          size_t ordinal,
                          TestNestability nestability);
   TestOrderedPendingTask(TestOrderedPendingTask&&);
   ~TestOrderedPendingTask();
 
   TestOrderedPendingTask& operator=(TestOrderedPendingTask&&);
 
   size_t ordinal;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestOrderedPendingTask);
 };
 
 TestMockTimeTaskRunner::TestOrderedPendingTask::TestOrderedPendingTask()
     : ordinal(0) {
 }
 
 TestMockTimeTaskRunner::TestOrderedPendingTask::TestOrderedPendingTask(
     TestOrderedPendingTask&&) = default;
 
 TestMockTimeTaskRunner::TestOrderedPendingTask::TestOrderedPendingTask(
     const tracked_objects::Location& location,
-    const Closure& task,
+    Closure task,
     TimeTicks post_time,
     TimeDelta delay,
     size_t ordinal,
     TestNestability nestability)
-    : base::TestPendingTask(location, task, post_time, delay, nestability),
+    : base::TestPendingTask(location,
+                            std::move(task),
+                            post_time,
+                            delay,
+                            nestability),
       ordinal(ordinal) {}
 
 TestMockTimeTaskRunner::TestOrderedPendingTask::~TestOrderedPendingTask() {
 }
 
 TestMockTimeTaskRunner::TestOrderedPendingTask&
 TestMockTimeTaskRunner::TestOrderedPendingTask::operator=(
     TestOrderedPendingTask&&) = default;
 
 // TestMockTimeTaskRunner -----------------------------------------------------
@@ skipping 104 matching lines @@
 
 // TODO(gab): Combine |thread_checker_| with a SequenceToken to differentiate
 // between tasks running in the scope of this TestMockTimeTaskRunner and other
 // task runners sharing this thread. http://crbug.com/631186
 bool TestMockTimeTaskRunner::RunsTasksOnCurrentThread() const {
   return thread_checker_.CalledOnValidThread();
 }
 
 bool TestMockTimeTaskRunner::PostDelayedTask(
     const tracked_objects::Location& from_here,
-    const Closure& task,
+    Closure task,
     TimeDelta delay) {
   AutoLock scoped_lock(tasks_lock_);
-  tasks_.push(TestOrderedPendingTask(from_here, task, now_ticks_, delay,
-                                     next_task_ordinal_++,
+  tasks_.push(TestOrderedPendingTask(from_here, std::move(task), now_ticks_,
+                                     delay, next_task_ordinal_++,
                                      TestPendingTask::NESTABLE));
   return true;
 }
 
 bool TestMockTimeTaskRunner::PostNonNestableDelayedTask(
     const tracked_objects::Location& from_here,
-    const Closure& task,
+    Closure task,
     TimeDelta delay) {
-  return PostDelayedTask(from_here, task, delay);
+  return PostDelayedTask(from_here, std::move(task), delay);
 }
 
 bool TestMockTimeTaskRunner::IsElapsingStopped() {
   return false;
 }
 
 void TestMockTimeTaskRunner::OnBeforeSelectingTask() {
   // Empty default implementation.
 }
 
@@ skipping 51 matching lines @@
     // It's safe to remove const and consume |task| here, since |task| is not
     // used for ordering the item.
     *next_task = std::move(const_cast<TestOrderedPendingTask&>(tasks_.top()));
     tasks_.pop();
     return true;
   }
   return false;
 }
 
 }  // namespace base