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

base/message_loop/message_loop.h

Index: base/message_loop/message_loop.h
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index 802fae0dd191e64034c1779c81263a83d1fe6492..d229c62e2d334d0d1a1cde6167250b22134380f4 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -446,10 +446,10 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
 
   // Calls RunTask or queues the pending_task on the deferred task list if it
   // cannot be run right now.  Returns true if the task was run.
-  bool DeferOrRunPendingTask(const PendingTask& pending_task);
+  bool DeferOrRunPendingTask(PendingTask pending_task);
 
   // Adds the pending task to delayed_work_queue_.
-  void AddToDelayedWorkQueue(const PendingTask& pending_task);
+  void AddToDelayedWorkQueue(PendingTask pending_task);
 
   // Delete tasks that haven't run yet without running them.  Used in the
   // destructor to make sure all the task's destructors get called.  Returns