Replace Closure in TaskRunner::PostTask with OneShotCallback

base/files/important_file_writer.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_FILES_IMPORTANT_FILE_WRITER_H_
 #define BASE_FILES_IMPORTANT_FILE_WRITER_H_
 
 #include <string>
 
 #include "base/base_export.h"
@@ skipping 87 matching lines @@
   // successful write event. Only one callback can be set at once.
   void RegisterOnNextSuccessfulWriteCallback(
       const Closure& on_next_successful_write);
 
   TimeDelta commit_interval() const {
     return commit_interval_;
   }
 
  private:
   // Helper method for WriteNow().
-  bool PostWriteTask(const Callback<bool()>& task);
+  bool PostWriteTask(OnceCallback<bool()> task);
 
   // If |result| is true and |on_next_successful_write_| is set, invokes
   // |on_successful_write_| and then resets it; no-ops otherwise.
   void ForwardSuccessfulWrite(bool result);
 
   // Invoked once and then reset on the next successful write event.
   Closure on_next_successful_write_;
 
   // Path being written to.
   const FilePath path_;
@@ skipping 11 matching lines @@
   const TimeDelta commit_interval_;
 
   WeakPtrFactory<ImportantFileWriter> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ImportantFileWriter);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_IMPORTANT_FILE_WRITER_H_