Keep non-key event handling in-house for NativeWidgetMus

ui/views/mus/native_widget_mus.cc

Index: ui/views/mus/native_widget_mus.cc
diff --git a/ui/views/mus/native_widget_mus.cc b/ui/views/mus/native_widget_mus.cc
index e52e56f722e8f3ae42e086a857ddeccd434a0938..081fa34674ed589fbe0f28ee26e546d9a25586f1 100644
--- a/ui/views/mus/native_widget_mus.cc
+++ b/ui/views/mus/native_widget_mus.cc
@@ -20,6 +20,7 @@
 #include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/client/window_tree_client.h"
 #include "ui/aura/env.h"
+#include "ui/aura/env_input_state_controller.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/mus/mus_util.h"
 #include "ui/aura/window.h"
@@ -485,6 +486,7 @@ NativeWidgetMus::NativeWidgetMus(internal::NativeWidgetDelegate* delegate,
       show_state_before_fullscreen_(mus::mojom::ShowState::DEFAULT),
       ownership_(Widget::InitParams::NATIVE_WIDGET_OWNS_WIDGET),
       content_(new aura::Window(this)),
+      aura_env_controller_(new aura::EnvInputStateController),
       close_widget_factory_(this) {
   window_->set_input_event_handler(this);
   mus_window_observer_.reset(new MusWindowObserver(this));
@@ -1317,9 +1319,16 @@ void NativeWidgetMus::OnWindowInputEvent(
   EventAckHandler ack_handler(std::move(*ack_callback));
 
   std::unique_ptr<ui::Event> event = ui::Event::Clone(event_in);
-  // TODO(markdittmer): This should be this->OnEvent(event.get()), but that
-  // can't happen until IME is refactored out of in WindowTreeHostMus.
-  platform_window_delegate()->DispatchEvent(event.get());
+
+  if (!event->IsKeyEvent()) {
+    if (event->IsMouseEvent())
+      aura_env_controller_->PreDispatchMouseEvent(event->AsMouseEvent());
+    OnEvent(event.get());
+  } else {
+    // TODO(markdittmer): This should be this->OnEvent(event.get()), but that
+    // can't happen until IME is refactored out of in WindowTreeHostMus.
+    platform_window_delegate()->DispatchEvent(event.get());
+  }
   // NOTE: |this| may be deleted.
 
   ack_handler.set_handled(event->handled());