IME for Mus: Send ack for key events after IME driver processes the event.

ui/views/mus/window_tree_host_mus.cc

 // Copyright 2015 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.
 
 #include "ui/views/mus/window_tree_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "services/ui/public/cpp/window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ skipping 35 matching lines @@
 
   // Initialize the stub platform window bounds to those of the ui::Window.
   platform_window()->SetBounds(window->bounds());
 
   // The location of events is already transformed, and there is no way to
   // correctly determine the reverse transform. So, don't attempt to transform
   // event locations, else the root location is wrong.
   // TODO(sky): we need to transform for device scale though.
   dispatcher()->set_transform_events(false);
   compositor()->SetHostHasTransparentBackground(true);
-
-  input_method_ = base::MakeUnique<InputMethodMus>(this, window);
-  SetSharedInputMethod(input_method_.get());
 }
 
 WindowTreeHostMus::~WindowTreeHostMus() {
   DestroyCompositor();
   DestroyDispatcher();
 }
 
-void WindowTreeHostMus::InitInputMethod(shell::Connector* connector) {
-  input_method_->Init(connector);
-}
-
 void WindowTreeHostMus::DispatchEvent(ui::Event* event) {
-  if (event->IsKeyEvent() && GetInputMethod()) {
-    GetInputMethod()->DispatchKeyEvent(event->AsKeyEvent());
-    return;
-  }
+  // Key events are sent to InputMethodMus directly from NativeWidgetMus.
+  DCHECK(!event->IsKeyEvent());
   WindowTreeHostPlatform::DispatchEvent(event);
 }
 
 void WindowTreeHostMus::OnClosed() {
   if (native_widget_)
     native_widget_->OnPlatformWindowClosed();
 }
 
 void WindowTreeHostMus::OnActivationChanged(bool active) {
   if (active)
     GetInputMethod()->OnFocus();
   else
     GetInputMethod()->OnBlur();
   if (native_widget_)
     native_widget_->OnActivationChanged(active);
   WindowTreeHostPlatform::OnActivationChanged(active);
 }
 
 void WindowTreeHostMus::OnCloseRequest() {
   OnHostCloseRequested();
 }
 
 gfx::ICCProfile WindowTreeHostMus::GetICCProfileForCurrentDisplay() {
   // TODO: This should read the profile from mus. crbug.com/647510
   return gfx::ICCProfile();
 }
 
 }  // namespace views