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

ui/aura/mus/input_method_mus.cc

Index: ui/aura/mus/input_method_mus.cc
diff --git a/ui/aura/mus/input_method_mus.cc b/ui/aura/mus/input_method_mus.cc
index c67c2228856e50ebafc545105de9f43de899ebb0..97643b0f47629b043705c3ac881b09992c9dedf1 100644
--- a/ui/aura/mus/input_method_mus.cc
+++ b/ui/aura/mus/input_method_mus.cc
@@ -45,17 +45,15 @@ void InputMethodMus::Init(service_manager::Connector* connector) {
 
 void InputMethodMus::DispatchKeyEvent(
     ui::KeyEvent* event,
-    std::unique_ptr<EventResultCallback> ack_callback) {
+    std::unique_ptr<AckCallback> ack_callback) {
   DCHECK(event->type() == ui::ET_KEY_PRESSED ||
          event->type() == ui::ET_KEY_RELEASED);
 
   // If no text input client, do nothing.
   if (!GetTextInputClient()) {
     DispatchKeyEventPostIME(event);
-    if (ack_callback) {
-      ack_callback->Run(event->handled() ? EventResult::HANDLED
-                                         : EventResult::UNHANDLED);
-    }
+    if (ack_callback)
+      ack_callback->Run(event->handled());
     return;
   }
 
@@ -121,7 +119,7 @@ bool InputMethodMus::IsCandidatePopupOpen() const {
 
 void InputMethodMus::SendKeyEventToInputMethod(
     const ui::KeyEvent& event,
-    std::unique_ptr<EventResultCallback> ack_callback) {
+    std::unique_ptr<AckCallback> ack_callback) {
   if (!input_method_) {
     // This code path is hit in tests that don't connect to the server.
     DCHECK(!ack_callback);
@@ -187,7 +185,7 @@ void InputMethodMus::UpdateTextInputType() {
 void InputMethodMus::AckPendingCallbacksUnhandled() {
   for (auto& callback_ptr : pending_callbacks_) {
     if (callback_ptr)
-      callback_ptr->Run(EventResult::UNHANDLED);
+      callback_ptr->Run(false);
   }
   pending_callbacks_.clear();
 }
@@ -198,20 +196,17 @@ void InputMethodMus::ProcessKeyEventCallback(
   // Remove the callback as DispatchKeyEventPostIME() may lead to calling
   // AckPendingCallbacksUnhandled(), which mutates |pending_callbacks_|.
   DCHECK(!pending_callbacks_.empty());
-  std::unique_ptr<EventResultCallback> ack_callback =
+  std::unique_ptr<AckCallback> ack_callback =
       std::move(pending_callbacks_.front());
   pending_callbacks_.pop_front();
-  EventResult event_result;
+  bool event_result = handled;
   if (!handled) {
     // If not handled by IME, try dispatching the event to delegate to see if
     // any client-side post-ime processing needs to be done. This includes cases
     // like backspace, return key, etc.
     std::unique_ptr<ui::Event> event_clone = ui::Event::Clone(event);
     DispatchKeyEventPostIME(event_clone->AsKeyEvent());
-    event_result =
-        event_clone->handled() ? EventResult::HANDLED : EventResult::UNHANDLED;
-  } else {
-    event_result = EventResult::HANDLED;
+    event_result = event_clone->handled();
   }
   // |ack_callback| can be null if the standard form of DispatchKeyEvent() is
   // called instead of the version which provides a callback. In mus+ash we