Revert of Remove remote tree host and some related input and metro_driver code

ui/base/ime/input_method_factory.cc

 // Copyright (c) 2012 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 "ui/base/ime/input_method_factory.h"
 
 #include "build/build_config.h"
 #include "ui/base/ime/mock_input_method.h"
 
 #if defined(OS_CHROMEOS)
 #include "ui/base/ime/input_method_chromeos.h"
 #elif defined(OS_WIN)
 #include "ui/base/ime/input_method_win.h"
+#include "ui/base/ime/remote_input_method_win.h"
 #elif defined(OS_MACOSX)
 #include "ui/base/ime/input_method_mac.h"
 #elif defined(USE_AURA) && defined(OS_LINUX) && defined(USE_X11) && \
       !defined(OS_CHROMEOS)
 #include "ui/base/ime/input_method_auralinux.h"
 #elif defined(OS_ANDROID)
 #include "ui/base/ime/input_method_android.h"
 #else
 #include "ui/base/ime/input_method_minimal.h"
 #endif
@@ skipping 21 matching lines @@
     g_input_method_for_testing = nullptr;
     return make_scoped_ptr(ret);
   }
 
   if (g_input_method_set_for_testing)
     return make_scoped_ptr(new MockInputMethod(delegate));
 
 #if defined(OS_CHROMEOS)
   return make_scoped_ptr(new InputMethodChromeOS(delegate));
 #elif defined(OS_WIN)
+  if (IsRemoteInputMethodWinRequired(widget))
+    return CreateRemoteInputMethodWin(delegate);
   return make_scoped_ptr(new InputMethodWin(delegate, widget));
 #elif defined(OS_MACOSX)
   return make_scoped_ptr(new InputMethodMac(delegate));
 #elif defined(USE_AURA) && defined(OS_LINUX) && defined(USE_X11) && \
       !defined(OS_CHROMEOS)
   return make_scoped_ptr(new InputMethodAuraLinux(delegate));
 #elif defined(OS_ANDROID)
   return make_scoped_ptr(new InputMethodAndroid(delegate));
 #else
   return make_scoped_ptr(new InputMethodMinimal(delegate));
@@ skipping 10 matching lines @@
       << "ui::SetUpInputMethodFactoryForTesting earlier.";
 
   g_input_method_set_for_testing = true;
 }
 
 void SetUpInputMethodForTesting(InputMethod* input_method) {
   g_input_method_for_testing = input_method;
 }
 
 }  // namespace ui