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

ui/base/ime/win/tsf_bridge.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_WIN_TSF_BRIDGE_H_
 #define UI_BASE_IME_WIN_TSF_BRIDGE_H_
 
 #include <Windows.h>
 #include <msctf.h>
 
@@ skipping 63 matching lines @@
   // Removes currently focused TextInputClient.
   // Caller must free |client|.
   virtual void RemoveFocusedClient(TextInputClient* client) = 0;
 
   // Obtains current thread manager.
   virtual base::win::ScopedComPtr<ITfThreadMgr> GetThreadManager() = 0;
 
   // Returns the focused text input client.
   virtual TextInputClient* GetFocusedTextInputClient() const = 0;
 
+  // Interface for for signalling candidate window events.
+  virtual void OnCandidateWindowShown() = 0;
+  virtual void OnCandidateWindowUpdated() = 0;
+  virtual void OnCandidateWindowHidden() = 0;
+
  protected:
   // Uses GetInstance() instead.
   TSFBridge();
 
  private:
   // Releases TLS instance.
   static void Finalize(void* data);
 
   DISALLOW_COPY_AND_ASSIGN(TSFBridge);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_IME_WIN_TSF_BRIDGE_H_