Fix a crash in PageActionImageView when extensions are reloaded due to incognito settings changing.

chrome/browser/ui/views/location_bar/page_action_image_view.h

 // Copyright (c) 2011 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_VIEWS_LOCATION_BAR_PAGE_ACTION_IMAGE_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_PAGE_ACTION_IMAGE_VIEW_H_
 #pragma once
 
 #include <map>
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/extensions/image_loading_tracker.h"
 #include "chrome/browser/extensions/extension_context_menu_model.h"
 #include "chrome/browser/ui/views/extensions/extension_popup.h"
 #include "views/controls/image_view.h"
 
 class LocationBarView;
 namespace views {
 class MenuRunner;
 }
 
 // PageActionImageView is used by the LocationBarView to display the icon for a
 // given PageAction and notify the extension when the icon is clicked.
 class PageActionImageView : public views::ImageView,
                             public ImageLoadingTracker::Observer,
                             public ExtensionContextMenuModel::PopupDelegate,
-                            public ExtensionPopup::Observer {
+                            public ExtensionPopup::Observer,
+                            public content::NotificationObserver {
  public:
   PageActionImageView(LocationBarView* owner,
                       ExtensionAction* page_action);
   virtual ~PageActionImageView();
 
   ExtensionAction* page_action() { return page_action_; }
 
   int current_tab_id() { return current_tab_id_; }
 
   void set_preview_enabled(bool preview_enabled) {
@@ skipping 12 matching lines @@
   virtual void OnImageLoaded(SkBitmap* image,
                              const ExtensionResource& resource,
                              int index) OVERRIDE;
 
   // Overridden from ExtensionContextMenuModelModel::Delegate
   virtual void InspectPopup(ExtensionAction* action) OVERRIDE;
 
   // Overridden from ExtensionPopup::Observer
   virtual void ExtensionPopupIsClosing(ExtensionPopup* popup) OVERRIDE;
 
+  // content::NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
   // Called to notify the PageAction that it should determine whether to be
   // visible or hidden. |contents| is the TabContents that is active, |url| is
   // the current page URL.
   void UpdateVisibility(TabContents* contents, const GURL& url);
 
   // Either notify listeners or show a popup depending on the page action.
   void ExecuteAction(int button, bool inspect_with_devtools);
 
  private:
   // Hides the active popup, if there is one.
@@ skipping 23 matching lines @@
   // The string to show for a tooltip;
   std::string tooltip_;
 
   // This is used for post-install visual feedback. The page_action icon is
   // briefly shown even if it hasn't been enabled by its extension.
   bool preview_enabled_;
 
   // The current popup and the button it came from.  NULL if no popup.
   ExtensionPopup* popup_;
 
+  content::NotificationRegistrar registrar_;
+
   scoped_ptr<views::MenuRunner> menu_runner_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PageActionImageView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_PAGE_ACTION_IMAGE_VIEW_H_