9/ Thin out dependencies

mojo/shell/background/BUILD.gn

 # Copyright 2016 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.
 
 group("background") {
   testonly = true
   deps = [
     ":lib",
     ":main",
   ]
 }
 
 source_set("lib") {
   sources = [
     "background_shell.cc",
     "background_shell.h",
   ]
   deps = [
     "//base",
     "//mojo/message_pump",
     "//mojo/shell",
     "//mojo/shell/public/cpp:sources",
+    "//mojo/shell/runner:init",
     "//mojo/shell/standalone:lib",
   ]
 }
 
 source_set("main") {
   sources = [
     "background_shell_main.cc",
     "background_shell_main.h",
   ]
   deps = [
     "//base",
     "//mojo/message_pump",
     "//mojo/shell",
     "//mojo/shell/public/cpp:sources",
+    "//mojo/shell/runner:init",
     "//mojo/shell/runner/common",
     "//mojo/shell/runner/host:lib",
     "//mojo/shell/standalone:lib",
   ]
 }