Cleans up gyp file for views example and removes duplicate code

ui/views/controls/table/table_view_observer.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 UI_VIEWS_CONTROLS_TABLE_TABLE_VIEW_OBSERVER_H_
 #define UI_VIEWS_CONTROLS_TABLE_TABLE_VIEW_OBSERVER_H_
 
 #include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/views/views_export.h"
 
 namespace views {
 
 class TableView;
 class TableView2;
 
 // TableViewObserver is notified about the TableView selection.
-class TableViewObserver {
+class VIEWS_EXPORT TableViewObserver {
  public:
   virtual ~TableViewObserver() {}
 
   // Invoked when the selection changes.
   virtual void OnSelectionChanged() = 0;
 
   // Optional method invoked when the user double clicks on the table.
   virtual void OnDoubleClick() {}
 
   // Optional method invoked when the user middle clicks on the table.
   virtual void OnMiddleClick() {}
 
   // Optional method invoked when the user hits a key with the table in focus.
   virtual void OnKeyDown(ui::KeyboardCode virtual_keycode) {}
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_TABLE_TABLE_VIEW_OBSERVER_H_