Use EventHandler for IME

ash/host/ash_window_tree_host_ozone.cc

Index: ash/host/ash_window_tree_host_ozone.cc
diff --git a/ash/host/ash_window_tree_host_ozone.cc b/ash/host/ash_window_tree_host_ozone.cc
index 4e1f09b53f5e31e3d04b0eb15bda900f74902c97..3926fdff12425cf19e57a6def2fa79834016e7de 100644
--- a/ash/host/ash_window_tree_host_ozone.cc
+++ b/ash/host/ash_window_tree_host_ozone.cc
@@ -8,6 +8,7 @@
 #include "ash/host/ash_window_tree_host_unified.h"
 #include "ash/host/root_window_transformer.h"
 #include "ash/host/transformer_helper.h"
+#include "ash/ime/input_method_event_handler.h"
 #include "base/command_line.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/aura/window.h"
@@ -46,6 +47,14 @@ class AshWindowTreeHostOzone : public AshWindowTreeHost,
   void SetBounds(const gfx::Rect& bounds) override;
   void DispatchEvent(ui::Event* event) override;
 
+  // ui::internal::InputMethodDelegate:
+  bool DispatchKeyEventPostIME(const ui::KeyEvent& event) override;
+
+  // ui::EventSource:
+  ui::EventDispatchDetails DeliverEventToProcessor(ui::Event* event) override {
+    return ui::EventSource::DeliverEventToProcessor(event);
+  }
+
   // Temporarily disable the tap-to-click feature. Used on CrOS.
   void SetTapToClickPaused(bool state);
 
@@ -132,6 +141,15 @@ void AshWindowTreeHostOzone::DispatchEvent(ui::Event* event) {
   SendEventToProcessor(event);
 }
 
+bool AshWindowTreeHostOzone::DispatchKeyEventPostIME(
+    const ui::KeyEvent& event) {
+  ui::KeyEvent event_copy(event);
+  input_method_handler()->SetPostIME(true);
+  ui::EventSource::DeliverEventToProcessor(&event_copy);
+  input_method_handler()->SetPostIME(false);
+  return event_copy.handled();
+}
+
 void AshWindowTreeHostOzone::SetTapToClickPaused(bool state) {
 #if defined(OS_CHROMEOS)
   DCHECK(ui::OzonePlatform::GetInstance()->GetInputController());