Support SetFocusedTextInputClient(NULL) in InputMethodTSF

ui/base/ime/input_method_tsf.cc

 // Copyright (c) 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.
 
 #include "ui/base/ime/input_method_tsf.h"
 
 #include "ui/base/ime/text_input_client.h"
 #include "ui/base/ime/win/tsf_bridge.h"
 
 namespace ui {
@@ skipping 71 matching lines @@
 
 void InputMethodTSF::CancelComposition(const TextInputClient* client) {
   if (IsTextInputClientFocused(client) && IsWindowFocused(client))
     ui::TSFBridge::GetInstance()->CancelComposition();
 }
 
 void InputMethodTSF::SetFocusedTextInputClient(TextInputClient* client) {
   if (IsWindowFocused(client)) {
     ui::TSFBridge::GetInstance()->SetFocusedClient(
         GetAttachedWindowHandle(client), client);
+  } else if (!client) {
+    // SetFocusedTextInputClient(NULL) must be interpreted as
+    // "Remove the attached client".
+    ui::TSFBridge::GetInstance()->RemoveFocusedClient(
+        ui::TSFBridge::GetInstance()->GetFocusedTextInputClient());
   }
   InputMethodWin::SetFocusedTextInputClient(client);
 }
 
 bool InputMethodTSF::IsCandidatePopupOpen() const {
   // TODO(yukishiino): Implement this method.
   return false;
 }
 
 void InputMethodTSF::OnWillChangeFocusedClient(TextInputClient* focused_before,
@@ skipping 30 matching lines @@
 }
 
 bool InputMethodTSF::IsWindowFocused(const TextInputClient* client) const {
   if (!client)
     return false;
   HWND attached_window_handle = GetAttachedWindowHandle(client);
   return attached_window_handle && GetFocus() == attached_window_handle;
 }
 
 }  // namespace ui