Convert GN single-item list concat to use lists.

tools/gn/secondary/chrome/BUILD.gn

 # Copyright (c) 2013 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("//crypto/ssl/flags.gni")
 import("//tools/grit/grit_rule.gni")
 
 executable("chrome") {
   sources = [
     "app/breakpad_field_trial_win.cc",
@@ skipping 33 matching lines @@
     ":common",
     ":debugger",
     ":plugin",
     ":renderer",
     ":utility",
     "//base",
   ]
 
   # TODO(brettw) this isn't right for all platforms.
   if (!use_aura) {
-    sources -= "app/chrome_exe_main_aura.cc"
+    sources -= [ "app/chrome_exe_main_aura.cc" ]
   }
 
   if (!is_win) {
     sources -= [
       "app/client_util.cc",
       "app/client_util.h",
     ]
   }
 }
 
 static_library("browser") {
   external = true
 
   if (is_linux) {
     libs = [ "dl" ]
     if (toolkit_uses_gtk) {
-      libs += "gconf-2"
+      libs += [ "gconf-2" ]
     }
   }
   if (is_linux) {
     configs += [
       "//build/config/linux:x11",
     ]
   }
 
   deps = [
     "//third_party/expat",
   ]
 }
 
 static_library("common") {
   external = true
 
   if (use_nss && is_linux) {
     # common/net uses NSS.
     # TODO(brettw) have a better way to express this without having to do
     # "if (use_nss)" everywhere.
-    configs += "//third_party/nss:nss_linux_config"
+    configs += [ "//third_party/nss:nss_linux_config" ]
   }
   deps = [
   ]
 }
 
 # TODO(brettw) move to browser/devtools/BUILD.gn
 source_set("debugger") {
   sources = [
     "browser/devtools/adb/android_rsa.cc",
     "browser/devtools/adb/android_rsa.h",
@@ skipping 196 matching lines @@
 #    ":theme_resources_gen",
 #    #"//ui:ui_resources",
 #  ]
 #}
 #
 ## TODO(brettw) rename "app_theme_resources" or something when we don't support
 ## GYP any more. This name is required to match the GYP build.
 #grit("theme_resources_gen") {
 #  source = "app/theme/theme_resources.grd"
 #}