GN Windows component build fixes.

content/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("//tools/grit/grit_rule.gni")
 
 # Applied by targets internal to content.
 config("content_implementation") {
   defines = [ "CONTENT_IMPLEMENTATION" ]
 }
@@ skipping 63 matching lines @@
 
 # This target exists to "hold" the content_export header so we can do proper
 # inclusion testing of it.
 source_set("export") {
   visibility = [ "//content/*" ]
   sources = [
     "content/common/content_export.h",
   ]
 }
 
-if (is_win) {
-  source_set("content_startup_helper_win") {
+# In the GYP build, this file is listed in several targets. In GN just have
+# those targets depend on this one. This can be depended on for any
+# platform for simplicity, and is a no-op on non-Windows.
+source_set("startup_helper_win") {
+  if (is_win) {
     sources = [
       "app/startup_helper_win.cc",
       "public/app/startup_helper_win.h",
     ]
 
     deps = [
       "//base",
       "//base:i18n",
       "//sandbox",
     ]
   }
 }