Make DispatchKeyEventPostIME() asynchronous.

chrome/browser/ui/views/ime_driver/input_method_bridge_chromeos.cc

 // Copyright 2016 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 "chrome/browser/ui/views/ime_driver/input_method_bridge_chromeos.h"
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/ui/views/ime_driver/remote_text_input_client.h"
 
 InputMethodBridge::InputMethodBridge(
     std::unique_ptr<RemoteTextInputClient> client)
     : client_(std::move(client)),
       input_method_chromeos_(
-          base::MakeUnique<ui::InputMethodChromeOS>(nullptr)) {
+          base::MakeUnique<ui::InputMethodChromeOS>(client_.get())) {
   input_method_chromeos_->SetFocusedTextInputClient(client_.get());
 }
 
 InputMethodBridge::~InputMethodBridge() {}
 
 void InputMethodBridge::OnTextInputTypeChanged(
     ui::TextInputType text_input_type) {
   client_->SetTextInputType(text_input_type);
   input_method_chromeos_->OnTextInputTypeChanged(client_.get());
 }
@@ skipping 13 matching lines @@
         key_event, base::MakeUnique<base::Callback<void(bool)>>(callback));
   } else {
     const bool handled = false;
     callback.Run(handled);
   }
 }
 
 void InputMethodBridge::CancelComposition() {
   input_method_chromeos_->CancelComposition(client_.get());
 }