Fix empty candidate window for IME Extension API.

chromeos/dbus/ibus/ibus_engine_service.cc

 // 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.
 
 #include "chromeos/dbus/ibus/ibus_engine_service.h"
 
 #include <string>
 #include "base/bind.h"
 #include "base/callback.h"
 #include "chromeos/dbus/ibus/ibus_constants.h"
@@ skipping 118 matching lines @@
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
   virtual ~IBusEngineServiceImpl() {
     bus_->UnregisterExportedObject(object_path_);
   }
 
   // IBusEngineService override.
   virtual void SetEngine(IBusEngineHandlerInterface* handler) OVERRIDE {
     DVLOG_IF(1, engine_handler_ != NULL) << "Replace engine.";
+    if (engine_handler_)
+      engine_handler_->Disable();
     engine_handler_ = handler;
   }
 
   // IBusEngineService override.
   virtual void UnsetEngine() OVERRIDE {
     LOG_IF(ERROR, engine_handler_ == NULL) << "There is no engine.";
     engine_handler_ = NULL;
   }
 
   // IBusEngineService override.
@@ skipping 425 matching lines @@
     DBusClientImplementationType type,
     dbus::Bus* bus,
     const dbus::ObjectPath& object_path) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
     return new IBusEngineServiceImpl(bus, object_path);
   else
     return new IBusEngineServiceDaemonlessImpl();
 }
 
 }  // namespace chromeos