Remove remote tree host and some related input and metro_driver code

win8/BUILD.gn

Index: win8/BUILD.gn
diff --git a/win8/BUILD.gn b/win8/BUILD.gn
index fb43d2da1da88998d8ad3308ddc540cb9a5e0597..7b36f33dc4498e04803c87011ff1538a147ade7a 100644
--- a/win8/BUILD.gn
+++ b/win8/BUILD.gn
@@ -2,31 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("metro_viewer_constants") {
-  sources = [
-    "viewer/metro_viewer_constants.cc",
-    "viewer/metro_viewer_constants.h",
-  ]
-}
-
-component("metro_viewer") {
-  sources = [
-    "viewer/metro_viewer_process_host.cc",
-    "viewer/metro_viewer_process_host.h",
-  ]
-
-  defines = [ "METRO_VIEWER_IMPLEMENTATION" ]
-
-  deps = [
-    ":metro_viewer_constants",
-    "//base",
-    "//ipc",
-    "//ui/aura",
-    "//ui/gfx",
-    "//ui/metro_viewer",
-  ]
-}
-
 source_set("test_support_win8") {
   sources = [
     "test/open_with_dialog_async.cc",