chromeos: Destruct DriveResourceMetadata on the blocking pool

chrome/browser/chromeos/drive/drive_file_system_util.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 CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_UTIL_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_UTIL_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/platform_file.h"
 #include "chrome/browser/chromeos/drive/drive_file_error.h"
 #include "chrome/browser/google_apis/gdata_errorcode.h"
 #include "googleurl/src/gurl.h"
 
 class Profile;
 
 namespace base {
 class FilePath;
 }
@@ skipping 111 matching lines @@
 void ConvertProtoToPlatformFileInfo(const PlatformFileInfoProto& proto,
                                     base::PlatformFileInfo* file_info);
 
 // Converts the platform file info to the proto representation.
 void ConvertPlatformFileInfoToProto(const base::PlatformFileInfo& file_info,
                                     PlatformFileInfoProto* proto);
 
 // Does nothing with |error|. Used with functions taking FileOperationCallback.
 void EmptyFileOperationCallback(DriveFileError error);
 
+// Helper to destroy objects which needs Destroy() to be called on destruction.
+template<typename T>

[hidehiko, 2013/03/18 13:16:28]

How about:

struct DestroyHelper {
  template<typename T>
  void operator()(T* object) const {
    if (object)
      object->Destroy();
  }
};

and

scoped_ptr<DriveCache, DestoryHelper> cache(new DriveCache);

?

[hashimoto, 2013/03/18 13:40:10]

Looks beautiful, done.

+struct DestroyHelper {
+  // scoped_ptr for T which calls Destroy() on destruction.
+  typedef scoped_ptr<T, DestroyHelper<T> > scoped_ptr;
+
+  void operator()(T* object) const {
+    if (object)
+      object->Destroy();
+  }
+};
+
 }  // namespace util
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_UTIL_H_