Replace Closure in TaskRunner::PostTask with OneShotCallback

base/pending_task.h

Index: base/pending_task.h
diff --git a/base/pending_task.h b/base/pending_task.h
index 5761653397e0e5d011522f56e786fa1cbbbcc373..9073fca8d424d9620181ce15b0977c33843c83c5 100644
--- a/base/pending_task.h
+++ b/base/pending_task.h
@@ -19,9 +19,9 @@ namespace base {
 // for use by classes that queue and execute tasks.
 struct BASE_EXPORT PendingTask : public TrackingInfo {
   PendingTask(const tracked_objects::Location& posted_from,
-              Closure task);
+              OnceClosure task);
   PendingTask(const tracked_objects::Location& posted_from,
-              Closure task,
+              OnceClosure task,
               TimeTicks delayed_run_time,
               bool nestable);
   PendingTask(PendingTask&& other);
@@ -33,7 +33,7 @@ struct BASE_EXPORT PendingTask : public TrackingInfo {
   bool operator<(const PendingTask& other) const;
 
   // The task to run.
-  Closure task;
+  OnceClosure task;
 
   // The site this PendingTask was posted from.
   tracked_objects::Location posted_from;