Add ExtendSelectionAndDelete() method to ui::TextInputClient.

ui/base/ime/text_input_client.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_BASE_IME_TEXT_INPUT_CLIENT_H_
 #define UI_BASE_IME_TEXT_INPUT_CLIENT_H_
 
 #include "base/basictypes.h"
 #include "base/i18n/rtl.h"
 #include "base/string16.h"
@@ skipping 109 matching lines @@
   // Called whenever current keyboard layout or input method is changed,
   // especially the change of input locale and text direction.
   virtual void OnInputMethodChanged() = 0;
 
   // Called whenever the user requests to change the text direction and layout
   // alignment of the current text box. It’s for supporting ctrl-shift on
   // Windows.
   // Returns false if the operation is not supported.
   virtual bool ChangeTextDirectionAndLayoutAlignment(
       base::i18n::TextDirection direction) = 0;
+
+  // Deletes the current selection plus the specified number of characters
+  // before and after the selection or caret.
+  virtual void ExtendSelectionAndDelete(size_t before, size_t after) = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_IME_TEXT_INPUT_CLIENT_H_