Implement a dummy host to do capturing and analysis only.

BUG=

Review-Url: https://codereview.chromium.org/1923573006
Cr-Original-Commit-Position: refs/heads/master@{#391855}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: dd0b05c54c79cf5e411d95b3c33a096e336b2aa8

config/linux/gtk2/BUILD.gn

@@ -30,6 +30,7 @@ group("gtk2") {
     "//remoting/host",
     "//remoting/host/it2me:remote_assistance_host",
     "//remoting/host:remoting_me2me_host_static",
+    "//remoting/test:it2me_standalone_host_main",
   ]
   public_configs = [ ":gtk2_internal_config" ]
 }