Clean up Mojo C API dependent targets

mojo/public/c/system/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.
 
 component("system") {
   output_name = "mojo_public_system"
 
   sources = [
     "buffer.h",
     "core.h",
@@ skipping 17 matching lines @@
 # mojo_native_application template in //mojo/public/mojo_application.gni.
 source_set("set_thunks_for_app") {
   sources = [
     "set_thunks_for_app.cc",
   ]
 
   public_deps = [
     ":system",
   ]
 }
-
-# TODO(rockot): Delete these deprecated aliases.
-
-group("for_shared_library") {
-  public_deps = [
-    ":system",
-  ]
-}
-
-group("for_component") {
-  public_deps = [
-    ":system",
-  ]
-}