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

ui/views/mus/window_manager_connection.cc

Index: ui/views/mus/window_manager_connection.cc
diff --git a/ui/views/mus/window_manager_connection.cc b/ui/views/mus/window_manager_connection.cc
index ef2f6eb5d490b098c39efb6c4a1b76f84a3047a8..cca48c31de6164d1b76465b31e2a93c08e9c3054 100644
--- a/ui/views/mus/window_manager_connection.cc
+++ b/ui/views/mus/window_manager_connection.cc
@@ -96,8 +96,10 @@ NativeWidget* WindowManagerConnection::CreateNativeWidgetMus(
   NativeWidgetMus::ConfigurePropertiesForNewWindow(init_params, &properties);
   properties[ui::mojom::WindowManager::kAppID_Property] =
       mojo::ConvertTo<std::vector<uint8_t>>(identity_.name());
-  return new NativeWidgetMus(delegate, NewWindow(properties),
-                             ui::mojom::SurfaceType::DEFAULT);
+  NativeWidgetMus* native_widget = new NativeWidgetMus(
+      delegate, NewWindow(properties), ui::mojom::SurfaceType::DEFAULT);
+  native_widget->window_tree_host()->InitInputMethod(connector_);
+  return native_widget;
 }
 
 const std::set<ui::Window*>& WindowManagerConnection::GetRoots() const {