Prefix string16 with base:: in ui/.

ui/views/examples/combobox_example.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_VIEWS_EXAMPLES_COMBOBOX_EXAMPLE_H_
 #define UI_VIEWS_EXAMPLES_COMBOBOX_EXAMPLE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/base/models/combobox_model.h"
 #include "ui/views/controls/combobox/combobox_listener.h"
 #include "ui/views/examples/example_base.h"
 
 namespace views {
 namespace examples {
 
 // A combobox model implementation that generates a list of "Item <index>".
 class ComboboxModelExample : public ui::ComboboxModel {
  public:
   ComboboxModelExample();
   virtual ~ComboboxModelExample();
 
   // Overridden from ui::ComboboxModel:
   virtual int GetItemCount() const OVERRIDE;
-  virtual string16 GetItemAt(int index) OVERRIDE;
+  virtual base::string16 GetItemAt(int index) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ComboboxModelExample);
 };
 
 class ComboboxExample : public ExampleBase, public ComboboxListener {
  public:
   ComboboxExample();
   virtual ~ComboboxExample();
 
   // Overridden from ExampleBase:
   virtual void CreateExampleView(View* container) OVERRIDE;
 
  private:
   // Overridden from ComboboxListener:
   virtual void OnSelectedIndexChanged(Combobox* combobox) OVERRIDE;
 
   ComboboxModelExample combobox_model_;
   Combobox* combobox_;
 
   DISALLOW_COPY_AND_ASSIGN(ComboboxExample);
 };
 
 }  // namespace examples
 }  // namespace views
 
 #endif  // UI_VIEWS_EXAMPLES_COMBOBOX_EXAMPLE_H_