Remove unused content .rc files.

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 50 matching lines @@
     deps = content_shared_components
   }
 }
 
 grit("resources") {
   source = "content_resources.grd"
   use_qualified_include = true
   outputs = [
     "grit/content_resources.h",
     "content_resources.pak",
-    "content_resources.rc",
   ]
 }
 
 # This target exists to "hold" the content_export header so we can do proper
 # inclusion testing of it.
 source_set("export") {
   visibility = [ "//content/*" ]
   sources = [
     "common/content_export.h",
   ]
 }
 
 # 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",
     ]
   }
 }