Cleanup: Remove unneeded headers from app/

chrome/browser/language_order_table_model.h

 // Copyright (c) 2009 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_LANGUAGE_ORDER_TABLE_MODEL_H_
 #define CHROME_BROWSER_LANGUAGE_ORDER_TABLE_MODEL_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "app/table_model.h"
-#include "app/table_model_observer.h"
+
+class TableModelObserver;
 
 class LanguageOrderTableModel : public TableModel {
  public:
   LanguageOrderTableModel();
 
   // Set Language List.
   void SetAcceptLanguagesString(const std::string& language_list);
 
   // Add at the end.  Return true if the language was added.
   bool Add(const std::string& language);
@@ skipping 30 matching lines @@
   // Set of entries we're showing.
   std::vector<std::string> languages_;
   std::string comma_separated_language_list_;
 
   TableModelObserver* observer_;
 
   DISALLOW_COPY_AND_ASSIGN(LanguageOrderTableModel);
 };
 
 #endif  // CHROME_BROWSER_LANGUAGE_ORDER_TABLE_MODEL_H_