WebUI: Add JavaScript lifecycle-control to WebUIMessageHandler.

chrome/browser/ui/webui/settings/font_handler.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 CHROME_BROWSER_UI_WEBUI_SETTINGS_FONT_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SETTINGS_FONT_HANDLER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 22 matching lines @@
 
 // Handle OS font list, font preference settings and character encoding.
 class FontHandler : public SettingsPageUIHandler,
                     public extensions::ExtensionRegistryObserver {
  public:
   explicit FontHandler(content::WebUI* webui);
   ~FontHandler() override;
 
   // SettingsPageUIHandler implementation.
   void RegisterMessages() override;
-  void RenderViewReused() override;
+  void OnJavascriptAllowed() override;
+  void OnJavascriptDisallowed() override;
 
   // ExtensionRegistryObserver implementation.
   void OnExtensionLoaded(content::BrowserContext* browser_context,
                          const extensions::Extension* extension) override;
   void OnExtensionUnloaded(
       content::BrowserContext* browser_context,
       const extensions::Extension* extension,
       extensions::UnloadedExtensionInfo::Reason reason) override;
 
  private:
@@ skipping 22 matching lines @@
   Profile* profile_;  // Weak pointer.
 
   base::WeakPtrFactory<FontHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FontHandler);
 };
 
 }  // namespace settings
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_FONT_HANDLER_H_