Remove some dead app host code.

chrome/browser/extensions/BUILD.gn

 # Copyright 2014 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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 
 gypi_values = exec_script(
     "//build/gypi_to_gn.py",
@@ skipping 179 matching lines @@
       deps += [ "//components/wifi" ]
       sources += rebase_path(
           gypi_values.chrome_browser_extensions_networking_private_sources,
           ".", "//chrome")
     }
 
     if (is_win) {
       deps += [
         "//third_party/iaccessible2",
         "//third_party/isimpledom",
-        #'launcher_support',  TODO(GYP)
       ]
     } else if (!is_chromeos) {
       sources += [ "api/system_display/display_info_provider_aura.cc" ]
     }
 
     if (use_openssl) {
       sources += [ "api/cast_channel/cast_auth_util_openssl.cc" ]
     } else {
       # cast_auth_util_nss.cc uses NSS functions.
       sources += [ "api/cast_channel/cast_auth_util_nss.cc" ]
@@ skipping 11 matching lines @@
           ".", "//chrome")
     }
 
     if (!use_ozone) {
       sources -= [
         "global_shortcut_listener_ozone.cc",
       ]
     }
   }
 }