Rework some UserScriptLoader logic in preparation to removing UserScript copy.

extensions/browser/web_ui_user_script_loader.h

 // Copyright 2015 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.
 
 #ifndef EXTENSIONS_BROWSER_WEB_UI_USER_SCRIPT_LOADER_H_
 #define EXTENSIONS_BROWSER_WEB_UI_USER_SCRIPT_LOADER_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 14 matching lines @@
  public:
   WebUIUserScriptLoader(content::BrowserContext* browser_context,
                         const HostID& host_id);
   ~WebUIUserScriptLoader() override;
 
  private:
   struct UserScriptRenderInfo;
   using UserScriptRenderInfoMap = std::map<int, UserScriptRenderInfo>;
 
   // UserScriptLoader:
-  void AddScripts(const std::set<extensions::UserScript>& scripts,
+  void AddScripts(const extensions::UserScriptList& scripts,
                   int render_process_id,
                   int render_frame_id) override;
   void LoadScripts(std::unique_ptr<extensions::UserScriptList> user_scripts,
                    const std::set<HostID>& changed_hosts,
                    const std::set<int>& added_script_ids,
                    LoadScriptsCallback callback) override;
 
   // Called at the end of each fetch, tracking whether all fetches are done.
   void OnSingleWebUIURLFetchComplete(extensions::UserScript::File* script_file,
                                      bool success,
@@ skipping 21 matching lines @@
   std::unique_ptr<extensions::UserScriptList> user_scripts_cache_;
 
   LoadScriptsCallback scripts_loaded_callback_;
 
   std::vector<std::unique_ptr<WebUIURLFetcher>> fetchers_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUIUserScriptLoader);
 };
 
 #endif  // EXTENSIONS_BROWSER_WEB_UI_USER_SCRIPT_LOADER_H_