Remove remote tree host and some related input and metro_driver code

ui/base/ime/BUILD.gn

 # 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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 component("ime") {
   output_name = "ui_base_ime"
   sources = [
@@ skipping 67 matching lines @@
     "input_method_win.h",
     "linux/fake_input_method_context.cc",
     "linux/fake_input_method_context.h",
     "linux/fake_input_method_context_factory.cc",
     "linux/fake_input_method_context_factory.h",
     "linux/linux_input_method_context.h",
     "linux/linux_input_method_context_factory.cc",
     "linux/linux_input_method_context_factory.h",
     "mock_input_method.cc",
     "mock_input_method.h",
-    "remote_input_method_delegate_win.h",
-    "remote_input_method_win.cc",
-    "remote_input_method_win.h",
     "text_input_client.cc",
     "text_input_client.h",
     "text_input_type.h",
     "ui_base_ime_export.h",
     "win/imm32_manager.cc",
     "win/imm32_manager.h",
     "win/tsf_input_scope.cc",
     "win/tsf_input_scope.h",
   ]
 
@@ skipping 78 matching lines @@
     libs = [ "imm32.lib" ]
   }
 
   if (use_ozone) {
     deps += [
       "//ui/events/ozone:events_ozone_layout",
       "//ui/ozone",
     ]
   }
 }