MD Settings: Update some Settings handlers to use new JS lifecycle management.

chrome/browser/ui/webui/settings/chromeos/change_picture_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_CHROMEOS_CHANGE_PICTURE_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_CHANGE_PICTURE_HANDLER_H_
 
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "chrome/browser/chromeos/camera_presence_notifier.h"
@@ skipping 23 matching lines @@
                              public ui::SelectFileDialog::Listener,
                              public content::NotificationObserver,
                              public ImageDecoder::ImageRequest,
                              public CameraPresenceNotifier::Observer {
  public:
   ChangePictureHandler();
   ~ChangePictureHandler() override;
 
   // WebUIMessageHandler implementation.
   void RegisterMessages() override;
+  void OnJavascriptAllowed() override;
+  void OnJavascriptDisallowed() override;
 
   // CameraPresenceNotifier::Observer implementation:
   void OnCameraPresenceCheckDone(bool is_camera_present) override;
 
  private:
   // Sends list of available default images to the page.
   void SendDefaultImages();
 
   // Sends current selection to the page.
   void SendSelectedImage();
@@ skipping 76 matching lines @@
 
   ScopedObserver<CameraPresenceNotifier, ChangePictureHandler> camera_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ChangePictureHandler);
 };
 
 }  // namespace settings
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_CHANGE_PICTURE_HANDLER_H_