Track original URL when downloading a redirected page

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 732a4eca3a09ec77bba2bbc4366e30faed6f2413..59a9ff18a0aaf3e46384c5da0bc9877907b33526 100644
--- a/chrome/browser/android/offline_pages/background_loader_offliner.cc
+++ b/chrome/browser/android/offline_pages/background_loader_offliner.cc
@@ -153,6 +153,14 @@ void BackgroundLoaderOffliner::DidStopLoading() {
   params.client_id = request.client_id();
   params.proposed_offline_id = request.request_id();
   params.is_background = true;
+
+  // Pass in the original URL if it is different from the last committed URL
+  // when redirects occur.

[fgorski, 2017/02/27 17:34:35]

please sync. I think Cathy was making a similar change recently.
It may make sense to add Cathy to this review.

[jianli, 2017/02/27 23:20:06]

Synced. Cathy ported my previous original URL change from prerender.

+  if (!request.original_url().is_empty())
+    params.original_url = request.original_url();
+  else if (params.url != request.url())
+    params.original_url = request.url();
+
   offline_page_model_->SavePage(
       params, std::move(archiver),
       base::Bind(&BackgroundLoaderOffliner::OnPageSaved,