Change {Obfuscated|Local}FileSystemFileUtil non-Singleton to take an underlying *FileUtil.

webkit/fileapi/local_file_system_file_util.h

Index: webkit/fileapi/local_file_system_file_util.h
diff --git a/webkit/fileapi/local_file_system_file_util.h b/webkit/fileapi/local_file_system_file_util.h
index 8b18f68e4e8bfd0588d74c84cae5264b9d3239a3..0f91be9f5d0765ba63f1ce569dd405aa66c588b4 100644
--- a/webkit/fileapi/local_file_system_file_util.h
+++ b/webkit/fileapi/local_file_system_file_util.h
@@ -13,7 +13,6 @@
 #include "base/file_util_proxy.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
-#include "base/memory/singleton.h"
 #include "base/platform_file.h"
 #include "base/tracked_objects.h"
 #include "webkit/fileapi/file_system_file_util.h"
@@ -36,7 +35,7 @@ class FileSystemOperationContext;
 
 class LocalFileSystemFileUtil : public FileSystemFileUtil {
  public:
-  static LocalFileSystemFileUtil* GetInstance();
+  explicit LocalFileSystemFileUtil(FileSystemFileUtil* underlying_file_util);

[kinuko, 2011/07/01 07:48:02]

I'm a bit concerned about this asymmetry-- if I read the code correctly some of
FSFUs are singletons but some are not right?  It's not very obvious whether a
FSFU pointer owner should call delete or not.  Now that we only create FSFU
instances per mount point, maybe we can turn all of the FSFU non-singleton?

[Dai Mikurube (NOT FULLTIME), 2011/07/04 06:14:53]

Yeah, I have the same concern.  ObfuscatedFSFU, however, has been already not
singleton -- asymmetric.

I'm planning to make the other FSFUs non-singleton in another change since they
might effect larger part.

[kinuko, 2011/07/05 03:13:02]

Ok.  Let me make sure, after this change only the 'top-level' FSFUs, which are
directly created by and owned by MountProviders will be non-singleton. Correct?

Could you add a comment to this class about who creates and owns an instance of
this class?
Also let's explicitly note that the |underlying_file_util| is *not* owned by
this instance and will need to be a singleton or to be deleted someone else. 
(Same for the constructor of obfuscatedFSFU's parameter)

[Dai Mikurube (NOT FULLTIME), 2011/07/05 05:30:11]

Ok, added comments on {Local|Obfuscated}FileSystemFileUtil.  Could you take a
look at this?

 
   virtual PlatformFileError CreateOrOpen(
       FileSystemOperationContext* context,
@@ -118,9 +117,6 @@ class LocalFileSystemFileUtil : public FileSystemFileUtil {
       const FilePath& root_path);
 
  protected:
-  LocalFileSystemFileUtil() { }
-
-  friend struct DefaultSingletonTraits<LocalFileSystemFileUtil>;
   DISALLOW_COPY_AND_ASSIGN(LocalFileSystemFileUtil);
 
  private:
@@ -131,6 +127,8 @@ class LocalFileSystemFileUtil : public FileSystemFileUtil {
       const GURL& origin_url,
       FileSystemType type,
       const FilePath& virtual_path);
+
+  FileSystemFileUtil* underlying_file_util_;
 };
 
 }  // namespace fileapi