chromeos: Destruct DriveResourceMetadata on the blocking pool

chrome/browser/chromeos/drive/drive_file_system_util.h

Index: chrome/browser/chromeos/drive/drive_file_system_util.h
diff --git a/chrome/browser/chromeos/drive/drive_file_system_util.h b/chrome/browser/chromeos/drive/drive_file_system_util.h
index 193cb8853da171c0a19f72695eab4ded15f458cb..eee73cbfecc04489a65a15ff89b893b253695f1b 100644
--- a/chrome/browser/chromeos/drive/drive_file_system_util.h
+++ b/chrome/browser/chromeos/drive/drive_file_system_util.h
@@ -8,6 +8,7 @@
 #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"
@@ -139,6 +140,18 @@ void ConvertPlatformFileInfoToProto(const base::PlatformFileInfo& file_info,
 // 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