IME for Mus: Make InputMethodMus use the IME Mojo API.

ui/views/mus/BUILD.gn

Index: ui/views/mus/BUILD.gn
diff --git a/ui/views/mus/BUILD.gn b/ui/views/mus/BUILD.gn
index 37065661ace3add30283f5c73a54550a1c8068df..701aed1295e62615bb5cee87a8e56c0f9561ad62 100644
--- a/ui/views/mus/BUILD.gn
+++ b/ui/views/mus/BUILD.gn
@@ -33,6 +33,8 @@ component("mus") {
     "screen_mus_delegate.h",
     "surface_context_factory.cc",
     "surface_context_factory.h",
+    "text_input_client_impl.cc",
+    "text_input_client_impl.h",
     "window_manager_connection.cc",
     "window_manager_connection.h",
     "window_manager_constants_converters.cc",
@@ -149,6 +151,7 @@ test("views_mus_unittests") {
 
   sources = [
     "display_list_unittest.cc",
+    "input_method_mus_unittest.cc",
     "native_widget_mus_unittest.cc",
     "os_exchange_data_provider_mus_unittest.cc",
     "pointer_watcher_event_router_unittest.cc",
@@ -198,6 +201,7 @@ test("views_mus_unittests") {
 
   data_deps = [
     ":unittests_manifest",
+    "//services/ui/ime/test_ime_driver",
     "//services/ui/test_wm",
   ]