Decouple FileSystem and WebSQL callbacks from VoidCallback and it non-refcounted

Source/modules/filesystem/FileSystemCallbacks.h

Index: Source/modules/filesystem/FileSystemCallbacks.h
diff --git a/Source/modules/filesystem/FileSystemCallbacks.h b/Source/modules/filesystem/FileSystemCallbacks.h
index 92db0c2eb7fb4677863abc391150637bcada6e6b..52949d6892525d7fb273a16fc028fa0723c32618 100644
--- a/Source/modules/filesystem/FileSystemCallbacks.h
+++ b/Source/modules/filesystem/FileSystemCallbacks.h
@@ -51,7 +51,7 @@ class FileWriterBase;
 class FileWriterBaseCallback;
 class MetadataCallback;
 class ExecutionContext;
-class VoidCallback;
+class FileSystemVoidCallback;
 
 class FileSystemCallbacksBase : public AsyncFileSystemCallbacks {
 public:
@@ -142,12 +142,12 @@ private:
 
 class VoidCallbacks : public FileSystemCallbacksBase {
 public:
-    static PassOwnPtr<AsyncFileSystemCallbacks> create(PassRefPtr<VoidCallback>, PassRefPtr<ErrorCallback>, DOMFileSystemBase*);
+    static PassOwnPtr<AsyncFileSystemCallbacks> create(PassRefPtr<FileSystemVoidCallback>, PassRefPtr<ErrorCallback>, DOMFileSystemBase*);
     virtual void didSucceed();
 
 private:
-    VoidCallbacks(PassRefPtr<VoidCallback>, PassRefPtr<ErrorCallback>, DOMFileSystemBase*);
-    RefPtr<VoidCallback> m_successCallback;
+    VoidCallbacks(PassRefPtr<FileSystemVoidCallback>, PassRefPtr<ErrorCallback>, DOMFileSystemBase*);
+    RefPtr<FileSystemVoidCallback> m_successCallback;
 };
 
 } // namespace