[SyncFS] Drop PostTaskAndReply from LocalToRemoteSyncer (5)

chrome/browser/sync_file_system/drive_backend/drive_backend_util.h

 // Copyright 2013 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 CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_DRIVE_BACKEND_UTIL_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_DRIVE_BACKEND_UTIL_H_
 
 #include <string>
 
+#include "base/bind.h"
+#include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
 #include "chrome/browser/sync_file_system/sync_status_code.h"
 #include "google_apis/drive/gdata_errorcode.h"
 #include "webkit/common/blob/scoped_file.h"
 
 namespace google_apis {
 class ChangeResource;
 class FileResource;
@@ skipping 56 matching lines @@
 const typename Container::mapped_type& LookUpMap(
     const Container& container,
     const typename Container::key_type& key,
     const typename Container::mapped_type& default_value) {
   typename Container::const_iterator found = container.find(key);
   if (found == container.end())
     return default_value;
   return found->second;
 }
 
+template <typename R, typename S, typename T>
+R ComposeFunction(const base::Callback<T()>& g,
+                  const base::Callback<R(S)>& f) {
+  return f.Run(g.Run());
+}
+
+template <typename R, typename S, typename T>
+base::Callback<R()> CreateComposedFunction(
+    const base::Callback<T()>& g,
+    const base::Callback<R(S)>& f) {
+  return base::Bind(&ComposeFunction<R, S, T>, g, f);
+}
+
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_DRIVE_BACKEND_UTIL_H_