MD Settings: Convert C++ handlers to be JavaScript-lifecycle aware.

chrome/browser/ui/webui/settings/search_engines_handler.h

 // Copyright 2016 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 CHROME_BROWSER_UI_WEBUI_SETTINGS_SEARCH_ENGINES_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SETTINGS_SEARCH_ENGINES_HANDLER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "chrome/browser/ui/search_engines/edit_search_engine_controller.h"
+#include "chrome/browser/ui/search_engines/keyword_editor_controller.h"
 #include "chrome/browser/ui/webui/settings/settings_page_ui_handler.h"
 #include "ui/base/models/table_model_observer.h"
 
-class KeywordEditorController;
 class Profile;
 
 namespace extensions {
 class Extension;
 }
 
 namespace settings {
 
 class SearchEnginesHandler : public SettingsPageUIHandler,
                              public ui::TableModelObserver,
                              public EditSearchEngineControllerDelegate {
  public:
   explicit SearchEnginesHandler(Profile* profile);
   ~SearchEnginesHandler() override;
 
   // ui::TableModelObserver implementation.
   void OnModelChanged() override;
   void OnItemsChanged(int start, int length) override;
   void OnItemsAdded(int start, int length) override;
   void OnItemsRemoved(int start, int length) override;
 
   // EditSearchEngineControllerDelegate implementation.
   void OnEditedKeyword(TemplateURL* template_url,
                        const base::string16& title,
                        const base::string16& keyword,
                        const std::string& url) override;
 
+  // SettingsPageUIHandler implementation.
   void RegisterMessages() override;
+  void OnJavascriptAllowed() override;
+  void OnJavascriptDisallowed() override;
 
  private:
-  std::unique_ptr<KeywordEditorController> list_controller_;
-  std::unique_ptr<EditSearchEngineController> edit_controller_;
-
   // Retrieves all search engines and returns the to WebUI.
   void HandleGetSearchEnginesList(const base::ListValue* args);
 
   std::unique_ptr<base::DictionaryValue> GetSearchEnginesList();
 
   // Removes the search engine at the given index. Called from WebUI.
   void HandleRemoveSearchEngine(const base::ListValue* args);
 
   // Sets the search engine at the given index to be default. Called from WebUI.
   void HandleSetDefaultSearchEngine(const base::ListValue* args);
@@ skipping 25 matching lines @@
 
   // Returns a dictionary to pass to WebUI representing the given search engine.
   base::DictionaryValue* CreateDictionaryForEngine(int index, bool is_default);
 
   // Returns a dictionary to pass to WebUI representing the extension.
   base::DictionaryValue* CreateDictionaryForExtension(
       const extensions::Extension& extension);
 
   Profile* const profile_;
 
+  KeywordEditorController list_controller_;
+  std::unique_ptr<EditSearchEngineController> edit_controller_;
+
   DISALLOW_COPY_AND_ASSIGN(SearchEnginesHandler);
 };
 
 }  // namespace settings
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_SEARCH_ENGINES_HANDLER_H_