Remove ScopedTempDir from sync test utility class

sync/test/engine/test_directory_setter_upper.h

Index: sync/test/engine/test_directory_setter_upper.h
diff --git a/sync/test/engine/test_directory_setter_upper.h b/sync/test/engine/test_directory_setter_upper.h
index 5dbce2d6cc5397d660f0622376da5cf81da9adf4..a8c5e5e9c3a67da992ad74d118a5a52662a6afcb 100644
--- a/sync/test/engine/test_directory_setter_upper.h
+++ b/sync/test/engine/test_directory_setter_upper.h
@@ -34,7 +34,6 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/scoped_temp_dir.h"
 #include "sync/test/fake_sync_encryption_handler.h"
 #include "sync/test/null_directory_change_delegate.h"
 #include "sync/util/test_unrecoverable_error_handler.h"
@@ -69,7 +68,6 @@ class TestDirectorySetterUpper {
 
   void RunInvariantCheck();
 
-  ScopedTempDir temp_dir_;
   FakeSyncEncryptionHandler encryption_handler_;
   scoped_ptr<syncable::Directory> directory_;
   std::string name_;