Merge to M57: Remove popup overlay from MHTML when requested

chrome/browser/android/offline_pages/background_loader_offliner.cc

Index: chrome/browser/android/offline_pages/background_loader_offliner.cc
diff --git a/chrome/browser/android/offline_pages/background_loader_offliner.cc b/chrome/browser/android/offline_pages/background_loader_offliner.cc
index fc4243f26ba82118c2b86cebcb62c63cadc13ddc..89d11b6df9f7a9ae0c280b15480b0b409a7355cb 100644
--- a/chrome/browser/android/offline_pages/background_loader_offliner.cc
+++ b/chrome/browser/android/offline_pages/background_loader_offliner.cc
@@ -139,6 +139,7 @@ void BackgroundLoaderOffliner::DidStopLoading() {
   params.url = web_contents->GetLastCommittedURL();
   params.client_id = request.client_id();
   params.proposed_offline_id = request.request_id();
+  params.is_background = true;
   offline_page_model_->SavePage(
       params, std::move(archiver),
       base::Bind(&BackgroundLoaderOffliner::OnPageSaved,