Oilpan: Ship Oilpan for SyncCallbackHelper, CreateFileResult and CallbackWrapper in filesystem/

These are leftovers when we shipped Oilpan for filesystem/ once.

BUG=340522

Review URL: https://codereview.chromium.org/501263003

git-svn-id: svn://svn.chromium.org/blink/trunk@180909 bbb929c8-8fbe-4397-9dbb-9b2b20218538
 DirectoryEntrySync* DirectoryEntrySync::getDirectory(const String& path, const Dictionary& options, ExceptionState& exceptionState)
 {
     FileSystemFlags flags(options);
    EntrySyncCallbackHelper* helper = EntrySyncCallbackHelper::create();
     m_fileSystem->getDirectory(this, path, flags, helper->successCallback(), helper->errorCallback(), DOMFileSystemBase::Synchronous);
     return static_cast<DirectoryEntrySync*>(helper->getResult(exceptionState));
 }

 DirectoryEntrySync* DirectoryEntrySync::getDirectory(const String& path, const Dictionary& options, ExceptionState& exceptionState)
 {
     FileSystemFlags flags(options);
    RefPtr<EntrySyncCallbackHelper> helper = EntrySyncCallbackHelper::create();
     m_fileSystem->getDirectory(this, path, flags, helper->successCallback(), helper->errorCallback(), DOMFileSystemBase::Synchronous);
     return static_cast<DirectoryEntrySync*>(helper->getResult(exceptionState));
 }
