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

third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
index 79503356b851cf354ffc12f40d93ef4b862e6fac..154491d76f0058b7811faac702a06ee33e7f7394 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
@@ -10,6 +10,7 @@
 #include <memory>
 #include <set>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/pending_task.h"
 #include "base/threading/thread_checker.h"
@@ -68,13 +69,13 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
    public:
     Task();
     Task(const tracked_objects::Location& posted_from,
-         const base::Closure& task,
+         base::Closure task,
          base::TimeTicks desired_run_time,
          EnqueueOrder sequence_number,
          bool nestable);
 
     Task(const tracked_objects::Location& posted_from,
-         const base::Closure& task,
+         base::Closure task,
          base::TimeTicks desired_run_time,
          EnqueueOrder sequence_number,
          bool nestable,
@@ -130,10 +131,10 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   void UnregisterTaskQueue() override;
   bool RunsTasksOnCurrentThread() const override;
   bool PostDelayedTask(const tracked_objects::Location& from_here,
-                       const base::Closure& task,
+                       base::Closure task,
                        base::TimeDelta delay) override;
   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
-                                  const base::Closure& task,
+                                  base::Closure task,
                                   base::TimeDelta delay) override;
   std::unique_ptr<QueueEnabledVoter> CreateQueueEnabledVoter() override;
   bool IsQueueEnabled() const override;
@@ -284,10 +285,10 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   ~TaskQueueImpl() override;
 
   bool PostImmediateTaskImpl(const tracked_objects::Location& from_here,
-                             const base::Closure& task,
+                             base::Closure task,
                              TaskType task_type);
   bool PostDelayedTaskImpl(const tracked_objects::Location& from_here,
-                           const base::Closure& task,
+                           base::Closure task,
                            base::TimeDelta delay,
                            TaskType task_type);
 
@@ -309,7 +310,7 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   // empty.
   void PushOntoImmediateIncomingQueueLocked(
       const tracked_objects::Location& posted_from,
-      const base::Closure& task,
+      base::Closure task,
       base::TimeTicks desired_run_time,
       EnqueueOrder sequence_number,
       bool nestable);