Auto hide app list on Windows when it loses focus.

ui/app_list/app_list_view.h

 // Copyright (c) 2012 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 UI_APP_LIST_APP_LIST_VIEW_H_
 #define UI_APP_LIST_APP_LIST_VIEW_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/app_list/app_list_export.h"
 #include "ui/app_list/search_box_view_delegate.h"
 #include "ui/app_list/search_result_list_view_delegate.h"
 #include "ui/views/bubble/bubble_delegate.h"
 #include "ui/views/controls/button/button.h"
 
+namespace views {
+class Widget;
+}
+
 namespace app_list {
 
 class AppListModel;
 class AppListViewDelegate;
 class ContentsView;
 class PaginationModel;
 class SearchBoxView;
 
 // AppListView is the top-level view and controller of app list UI. It creates
 // and hosts a AppsGridView and passes AppListModel to it for display.
@@ skipping 41 matching lines @@
   // Overridden from SearchBoxViewDelegate:
   virtual void QueryChanged(SearchBoxView* sender) OVERRIDE;
 
   // Overridden from SearchResultListViewDelegate:
   virtual void OpenResult(const SearchResult& result,
                           int event_flags) OVERRIDE;
   virtual void InvokeResultAction(const SearchResult& result,
                                   int action_index,
                                   int event_flags) OVERRIDE;
 
+  // Overridden from views::WidgetObserver:
+  virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE;
+  virtual void OnWidgetActivationChanged(views::Widget* widget, bool active)
+      OVERRIDE;
+
   scoped_ptr<AppListModel> model_;
   scoped_ptr<AppListViewDelegate> delegate_;
 
   SearchBoxView* search_box_view_;  // Owned by views hierarchy.
   ContentsView* contents_view_;  // Owned by views hierarchy.
 
   DISALLOW_COPY_AND_ASSIGN(AppListView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_APP_LIST_VIEW_H_