An edit for SetText needs to be merged with previous edit for omnibox.

views/controls/textfield/native_textfield_wrapper.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 VIEWS_CONTROLS_TEXTFIELD_NATIVE_TEXTFIELD_WRAPPER_H_
 #define VIEWS_CONTROLS_TEXTFIELD_NATIVE_TEXTFIELD_WRAPPER_H_
 #pragma once
 
 #include "base/string16.h"
 #include "ui/gfx/native_widget_types.h"
@@ skipping 120 matching lines @@
   virtual TextStyle* CreateTextStyle() = 0;
 
   // Applies the |style| to the text specified by the |range|.
   // See |Textfield::ApplyTextStyle| for detail.
   virtual void ApplyTextStyle(const TextStyle* style,
                               const ui::Range& range) = 0;
 
   // Clears all text styles in this textfield.
   virtual void ClearAllTextStyles() = 0;
 
+  // Clears Edit history.
+  virtual void ClearEditHistory() = 0;
+
   // Creates an appropriate NativeTextfieldWrapper for the platform.
   static NativeTextfieldWrapper* CreateWrapper(Textfield* field);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_TEXTFIELD_NATIVE_TEXTFIELD_WRAPPER_H_