Fixes compile bugs for views on gtk.

views/controls/combobox/native_combobox_gtk.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 VIEWS_CONTROLS_COMBOBOX_NATIVE_COMBOBOX_GTK_H_
 #define VIEWS_CONTROLS_COMBOBOX_NATIVE_COMBOBOX_GTK_H_
 
 #include "views/controls/combobox/native_combobox_wrapper.h"
 #include "views/controls/native_control_gtk.h"
 
 namespace views {
 
 class NativeComboboxGtk : public NativeControlGtk,
                           public NativeComboboxWrapper {
  public:
   explicit NativeComboboxGtk(Combobox* combobox);
   virtual ~NativeComboboxGtk();
 
   // Overridden from NativeComboboxWrapper:
   virtual void UpdateFromModel();
   virtual void UpdateSelectedItem();
   virtual void UpdateEnabled();
   virtual int GetSelectedItem() const;
   virtual bool IsDropdownOpen() const;
   virtual gfx::Size GetPreferredSize() const;
   virtual View* GetView();
   virtual void SetFocus();
+  virtual gfx::NativeView GetTestingHandle() const;
 
  protected:
   // Overridden from NativeControlGtk:
   virtual void CreateNativeControl();
   virtual void NativeControlCreated(GtkWidget* widget);
-  
+
  private:
   // The combobox we are bound to.
   Combobox* combobox_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeComboboxGtk);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_COMBOBOX_NATIVE_COMBOBOX_GTK_H_