net_watcher: Stop linking against glib/gconf/gio.

net/BUILD.gn

Index: net/BUILD.gn
diff --git a/net/BUILD.gn b/net/BUILD.gn
index ec969096a1e666cbeb6665b6d3161f433b1b50c6..fe3c88856ec5e905906f4ab09b72ba611435afaf 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -973,14 +973,6 @@ if (!is_ios && !is_android) {
         "//build/config/sanitizers:deps",
         "//build/win:default_exe_manifest",
       ]
-
-      if (is_desktop_linux && use_gconf && use_glib && use_gio) {
-        configs += [
-          "//build/config/linux/gconf",
-          "//build/config/linux:glib",
-        ]
-        deps += [ "//build/linux/libgio" ]
-      }
     }
   }