Makes sure that an input method doesn't reference to a destroyed object.

ui/base/ime/dummy_input_method.cc

 // 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.
 
 #include "ui/base/ime/dummy_input_method.h"
 
 namespace ui {
 
 DummyInputMethod::DummyInputMethod() {
 }
@@ skipping 14 matching lines @@
 }
 
 bool DummyInputMethod::OnUntranslatedIMEMessage(const base::NativeEvent& event,
                                                 NativeEventResult* result) {
   return false;
 }
 
 void DummyInputMethod::SetFocusedTextInputClient(TextInputClient* client) {
 }
 
+void DummyInputMethod::DetachTextInputClient(TextInputClient* client) {
+}
+
 TextInputClient* DummyInputMethod::GetTextInputClient() const {
   return NULL;
 }
 
 bool DummyInputMethod::DispatchKeyEvent(const base::NativeEvent& event) {
   return false;
 }
 
 bool DummyInputMethod::DispatchFabricatedKeyEvent(const ui::KeyEvent& event) {
   return false;
@@ skipping 40 matching lines @@
 }
 
 void DummyInputMethod::AddObserver(InputMethodObserver* observer) {
 }
 
 void DummyInputMethod::RemoveObserver(InputMethodObserver* observer) {
 }
 
 }  // namespace ui