Make chrome GN build work in component mode.

content/ppapi_plugin/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.
 
 source_set("ppapi_plugin") {
+  visibility = [ "//content/*" ]
+
   sources = [
     "broker_process_dispatcher.cc",
     "broker_process_dispatcher.h",
     "plugin_process_dispatcher.cc",
     "plugin_process_dispatcher.h",
     "ppapi_broker_main.cc",
     "ppapi_plugin_main.cc",
     "ppapi_thread.cc",
     "ppapi_thread.h",
     "ppapi_webkitplatformsupport_impl.cc",
     "ppapi_webkitplatformsupport_impl.h",
   ]
 
   configs += [ "//content:content_implementation" ]
 
   deps = [
     "//base",
     "//content:export",
+    "//content/public/child:child_sources",
+    "//content/public/common:common_sources",
     "//mojo/public/interfaces/application",
     "//ppapi:ppapi_ipc",
     "//skia",
     "//third_party/icu",
     "//third_party/WebKit/public:blink",
     "//ui/base",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 }