IME for Mus: Use ui::InputMethodChromeOS to provide logic for ime driver.

ui/views/mus/text_input_client_impl.cc

Index: ui/views/mus/text_input_client_impl.cc
diff --git a/ui/views/mus/text_input_client_impl.cc b/ui/views/mus/text_input_client_impl.cc
index 9e5b21621b359579720eeaf1aa22fb1f922207a4..4193e127e280382d4610a27dd6fec609f109ddb8 100644
--- a/ui/views/mus/text_input_client_impl.cc
+++ b/ui/views/mus/text_input_client_impl.cc
@@ -38,9 +38,7 @@ void TextInputClientImpl::InsertText(const std::string& text) {
 
 void TextInputClientImpl::InsertChar(std::unique_ptr<ui::Event> event) {
   DCHECK(event->IsKeyEvent());
-  ui::KeyEvent* key_event = event->AsKeyEvent();
-  DCHECK(key_event->is_char());
-  text_input_client_->InsertChar(*key_event);
+  text_input_client_->InsertChar(*event->AsKeyEvent());
 }
 
 }  // namespace views