ui: Cleanup class/struct forward declarations

ui/app_list/views/search_box_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_VIEWS_SEARCH_BOX_VIEW_H_
 #define UI_APP_LIST_VIEWS_SEARCH_BOX_VIEW_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "ui/app_list/search_box_model_observer.h"
 #include "ui/app_list/speech_ui_model_observer.h"
 #include "ui/gfx/shadow_value.h"
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/controls/textfield/textfield_controller.h"
 #include "ui/views/view.h"
 
 namespace views {
-class ImageView;
 class Textfield;
 }  // namespace views
 
 namespace app_list {
 
 // Possible locations for partial keyboard focus (but note that the search
 // box always handles typing).
 enum SearchBoxFocus {
   FOCUS_BACK_BUTTON,    // Back button, only responds to ENTER
   FOCUS_SEARCH_BOX,     // Nothing else has partial focus
@@ skipping 91 matching lines @@
   views::View* contents_view_;  // Owned by views hierarchy.
 
   SearchBoxFocus focused_view_;  // Which element has TAB'd focus.
 
   DISALLOW_COPY_AND_ASSIGN(SearchBoxView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_SEARCH_BOX_VIEW_H_