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

win8/metro_driver/metro_driver.h

Index: win8/metro_driver/metro_driver.h
diff --git a/win8/metro_driver/metro_driver.h b/win8/metro_driver/metro_driver.h
new file mode 100644
index 0000000000000000000000000000000000000000..da8f1c61282a305958bd9c78cbc6595c3534142f
--- /dev/null
+++ b/win8/metro_driver/metro_driver.h
@@ -0,0 +1,17 @@
+// 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.
+
+#ifndef WIN8_METRO_DRIVER_METRO_DRIVER_H_
+#define WIN8_METRO_DRIVER_METRO_DRIVER_H_
+
+#include "stdafx.h"
+
+class ChromeAppViewFactory
+    : public mswr::RuntimeClass<winapp::Core::IFrameworkViewSource> {
+ public:
+  ChromeAppViewFactory(winapp::Core::ICoreApplication* icore_app);
+  IFACEMETHOD(CreateView)(winapp::Core::IFrameworkView** view) override;
+};
+
+#endif  // WIN8_METRO_DRIVER_METRO_DRIVER_H_