[FYI] All-in-one OnCandidateWindow{Show,Update,Hide}

ui/views/controls/prefix_selector.h

 // Copyright 2013 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_CONTROLS_PREFIX_SELECTOR_H_
 #define UI_VIEWS_CONTROLS_PREFIX_SELECTOR_H_
 
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "ui/base/ime/text_input_client.h"
@@ skipping 33 matching lines @@
   virtual bool GetSelectionRange(gfx::Range* range) const OVERRIDE;
   virtual bool SetSelectionRange(const gfx::Range& range) OVERRIDE;
   virtual bool DeleteRange(const gfx::Range& range) OVERRIDE;
   virtual bool GetTextFromRange(const gfx::Range& range,
                                 string16* text) const OVERRIDE;
   virtual void OnInputMethodChanged() OVERRIDE;
   virtual bool ChangeTextDirectionAndLayoutAlignment(
       base::i18n::TextDirection direction) OVERRIDE;
   virtual void ExtendSelectionAndDelete(size_t before, size_t after) OVERRIDE;
   virtual void EnsureCaretInRect(const gfx::Rect& rect) OVERRIDE;
+  virtual void OnCandidateWindowShow() OVERRIDE {}
+  virtual void OnCandidateWindowUpdate() OVERRIDE {}
+  virtual void OnCandidateWindowHide() OVERRIDE {}
 
  private:
   // Invoked when text is typed. Tries to change the selection appropriately.
   void OnTextInput(const string16& text);
 
   // Returns true if the text of the node at |row| starts with |lower_text|.
   bool TextAtRowMatchesText(int row, const string16& lower_text);
 
   // Clears |current_text_| and resets |time_of_last_key_|.
   void ClearText();
 
   PrefixDelegate* prefix_delegate_;
 
   // Time OnTextInput() was last invoked.
   base::TimeTicks time_of_last_key_;
 
   string16 current_text_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefixSelector);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_PREFIX_SELECTOR_H_