Enable Config::MUS to use classic IME instead of servicified IME.

ui/aura/mus/window_tree_host_mus_init_params.h

 // Copyright 2017 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_AURA_MUS_WINDOW_TREE_HOST_MUS_INIT_PARAMS_H_
 #define UI_AURA_MUS_WINDOW_TREE_HOST_MUS_INIT_PARAMS_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 47 matching lines @@
   std::map<std::string, std::vector<uint8_t>> properties;
 
   cc::FrameSinkId frame_sink_id;
 
   // Id of the display the window should be created on.
   int64_t display_id = 0;
 
   // Used when the WindowTreeHostMus corresponds to a new display manually
   // created by the window manager.
   std::unique_ptr<DisplayInitParams> display_init_params;
+
+  // Use classic IME (i.e. InputMethodChromeOS) instead of servicified IME
+  // (i.e. InputMethodMus).
+  bool use_classic_ime = false;
 };
 
 // Creates a WindowTreeHostMusInitParams that is used when creating a top-level
 // window.
 AURA_EXPORT WindowTreeHostMusInitParams CreateInitParamsForTopLevel(
     WindowTreeClient* window_tree_client,
     std::map<std::string, std::vector<uint8_t>> properties =
         std::map<std::string, std::vector<uint8_t>>());
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_TREE_HOST_MUS_INIT_PARAMS_H_