Unify IMEDriver and IMEServer.

services/ui/ime/ime_registrar_impl.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 "services/ui/ime/ime_registrar_impl.h"
 
 namespace ui {
 
-IMERegistrarImpl::IMERegistrarImpl(IMEServerImpl* ime_server)
-    : ime_server_(ime_server) {}
+IMERegistrarImpl::IMERegistrarImpl(IMEDriverBridge* ime_driver_bridge)
+    : ime_driver_bridge_(ime_driver_bridge) {}
 
 IMERegistrarImpl::~IMERegistrarImpl() {}
 
 void IMERegistrarImpl::AddBinding(mojom::IMERegistrarRequest request) {
   bindings_.AddBinding(this, std::move(request));
 }
 
 void IMERegistrarImpl::RegisterDriver(mojom::IMEDriverPtr driver) {
   // TODO(moshayedi): crbug.com/634441. IMERegistrarImpl currently identifies
   // the last registered driver as the current driver. Rethink this once we
   // have more usecases.
-  ime_server_->OnDriverChanged(std::move(driver));
+  ime_driver_bridge_->SetDriver(std::move(driver));
 }
 }  // namespace ui