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

content/browser/download/save_file_manager.h

 // 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.
 //
 // Objects that handle file operations for saving files, on the file thread.
 //
 // The SaveFileManager owns a set of SaveFile objects, each of which connects
 // with a SaveItem object which belongs to one SavePackage and runs on the file
 // thread for saving data in order to avoid disk activity on either network IO
 // thread or the UI thread. It coordinates the notifications from the network
@@ skipping 72 matching lines @@
 class SavePackage;
 struct Referrer;
 
 class SaveFileManager : public base::RefCountedThreadSafe<SaveFileManager> {
  public:
   SaveFileManager();
 
   // Lifetime management.
   CONTENT_EXPORT void Shutdown();
 
-  // Save the specified URL. Called on the UI thread and forwarded to the
-  // ResourceDispatcherHostImpl on the IO thread.
+  // Save the specified URL.  Caller has to guarantee that |save_package| will
+  // be alive until the call to RemoveSaveFile.  Called on the UI thread (and in
+  // case of network downloads forwarded to the ResourceDispatcherHostImpl on
+  // the IO thread).
   void SaveURL(SaveItemId save_item_id,
                const GURL& url,
                const Referrer& referrer,
                int render_process_host_id,
                int render_view_routing_id,
                int render_frame_routing_id,
                SaveFileCreateInfo::SaveFileSource save_source,
                const base::FilePath& file_full_path,
                ResourceContext* context,
                SavePackage* save_package);
@@ skipping 108 matching lines @@
   using SavePackageMap =
       std::unordered_map<SaveItemId, SavePackage*, SaveItemId::Hasher>;
   SavePackageMap packages_;
 
   DISALLOW_COPY_AND_ASSIGN(SaveFileManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_SAVE_FILE_MANAGER_H_