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

win8/metro_driver/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("//chrome/version.gni")
 import("//testing/test.gni")
 
 shared_library("metro_driver") {
   sources = [
     "display_properties.cc",
     "display_properties.h",
+    "metro_driver.cc",
+    "metro_driver.h",
+    "metro_driver_win7.cc",
     "stdafx.h",
     "winrt_utils.cc",
     "winrt_utils.h",
   ]
 
   deps = [
     ":copy_resources",
     ":version_resources",
     "//base",
     "//chrome/common:constants",
     "//chrome/installer/util:with_no_strings",
     "//crypto",
     "//ipc",
     "//sandbox",
     "//ui/events",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/metro_viewer",
     "//url",
   ]
 
   if (use_aura) {
     sources += [
+      "chrome_app_view_ash.cc",
+      "chrome_app_view_ash.h",
       "direct3d_helper.cc",
       "direct3d_helper.h",
+      "file_picker_ash.cc",
+      "file_picker_ash.h",
     ]
 
     deps += [
       "//ui/events:gesture_detection",
+      "//win8:metro_viewer_constants",
       "//win8/metro_driver/ime",
     ]
   } else {
     sources = [
       "chrome_app_view.cc",
       "chrome_app_view.h",
       "chrome_url_launch_handler.cc",
       "chrome_url_launch_handler.h",
       "devices_handler.cc",
       "devices_handler.h",
+      "file_picker.cc",
+      "file_picker.h",
       "metro_dialog_box.cc",
       "metro_dialog_box.h",
       "print_document_source.cc",
       "print_document_source.h",
       "print_handler.cc",
       "print_handler.h",
       "secondary_tile.cc",
       "secondary_tile.h",
       "settings_handler.cc",
       "settings_handler.h",
@@ skipping 47 matching lines @@
     "winrt_utils_unittest.cc",
   ]
 
   deps = [
     ":metro_driver",
     "//base",
     "//chrome/installer/util:with_rc_strings",
     "//testing/gtest",
   ]
 }