Deleted AppListViewDelegateObserver class (was unused).

ui/app_list/views/app_list_view.h

Index: ui/app_list/views/app_list_view.h
diff --git a/ui/app_list/views/app_list_view.h b/ui/app_list/views/app_list_view.h
index 1d8c915dfb86ac9be19a4e4c2b4b47df7a30e231..a3dbfbb21aa652ab9dacfa2bc070f20b9c4bb6b6 100644
--- a/ui/app_list/views/app_list_view.h
+++ b/ui/app_list/views/app_list_view.h
@@ -12,7 +12,6 @@
 #include "base/observer_list.h"
 #include "build/build_config.h"
 #include "ui/app_list/app_list_export.h"
-#include "ui/app_list/app_list_view_delegate_observer.h"
 #include "ui/app_list/speech_ui_model_observer.h"
 #include "ui/views/bubble/bubble_dialog_delegate.h"
 #include "ui/views/widget/widget.h"
@@ -43,7 +42,6 @@ class AppListViewTestApi;
 // 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.
 class APP_LIST_EXPORT AppListView : public views::BubbleDialogDelegateView,
-                                    public AppListViewDelegateObserver,
                                     public SpeechUIModelObserver {
  public:
   // Does not take ownership of |delegate|.
@@ -98,9 +96,6 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDialogDelegateView,
       gfx::NativeView child,
       const gfx::Point& location) override;
 
-  // Overridden from AppListViewDelegateObserver:
-  void OnShutdown() override;
-
   void SetProfileByPath(const base::FilePath& profile_path);
 
   void AddObserver(AppListViewObserver* observer);