Add the method to check if offline archive is in internal dir

Bug: 758690
Change-Id: I8bb4283fc40a87fa7a87df2c7e513e2e16903290
Reviewed-on: https://chromium-review.googlesource.com/828049
Reviewed-by: Filip Gorski <fgorski@chromium.org>
Commit-Queue: Jian Li <jianli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524232}
void OfflinePageModelImpl::AddPage(const OfflinePageItem& page,
                                   const AddPageCallback& callback) {
  RunWhenLoaded(base::Bind(&OfflinePageModelImpl::AddPageWhenLoadDone,
                           weak_ptr_factory_.GetWeakPtr(), page, callback));
}

void OfflinePageModelImpl::AddPage(const OfflinePageItem& page,
                                   const AddPageCallback& callback) {
  RunWhenLoaded(base::Bind(&OfflinePageModelImpl::AddPageWhenLoadDone,
                           weak_ptr_factory_.GetWeakPtr(), page, callback));
}
