Fix how Save-Page-As responds to web requests blocked by extensions.

content/browser/download/save_package.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/download/save_package.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 991 matching lines @@
 
   // Collect all saved success items.
   // SECURITY NOTE: We don't send *all* urls / local paths, but only
   // those that the given frame had access to already (because it contained
   // the savable resources / subframes associated with save items).
   std::map<GURL, base::FilePath> url_to_local_path;
   auto it = frame_tree_node_id_to_contained_save_items_.find(
       target_frame_tree_node_id);
   if (it != frame_tree_node_id_to_contained_save_items_.end()) {
     for (SaveItem* save_item : it->second) {
-      DCHECK(save_item->has_final_name());
+      // Skip items that failed to save.
+      if (!save_item->has_final_name()) {
+        DCHECK_EQ(SaveItem::SaveState::COMPLETE, save_item->state());
+        DCHECK(!save_item->success());
+        continue;
+      }
+
+      // Calculate the relative path for referring to the |save_item|.
       base::FilePath local_path(base::FilePath::kCurrentDirectory);
       if (target_tree_node->IsMainFrame()) {
         local_path = local_path.Append(saved_main_directory_path_.BaseName());
       }
       local_path = local_path.Append(save_item->file_name());
       url_to_local_path[save_item->url()] = local_path;
     }
   }
 
   // Ask target frame to serialize itself.
@@ skipping 471 matching lines @@
 
 void SavePackage::FinalizeDownloadEntry() {
   DCHECK(download_);
   DCHECK(download_manager_);
 
   download_manager_->OnSavePackageSuccessfullyFinished(download_);
   StopObservation();
 }
 
 }  // namespace content