Convert GN visibility variables to lists.

build/secondary/third_party/nss/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("//build/config/linux/pkg_config.gni")
 
 if (is_linux) {
   # This is a dependency on NSS with no libssl. On Linux we use a built-in SSL
   # library but the system NSS libraries. Non-Linux platforms using NSS use the
   # hermetic one in //third_party/nss.
@@ skipping 367 matching lines @@
   # "exclude_nss_root_certs" is not specified, as "nss_static" depends on
   # the "builtinsC_GetFunctionList" exported by this target. This is an
   # artifact of how NSS is being statically built, which is not an
   # officially supported configuration - normally, "nssckbi.dll/so" would
   # depend on libnss3.dll/so, and the higher layer caller would instruct
   # libnss3.dll to dynamically load nssckbi.dll, breaking the circle.
   #
   # TODO(rsleevi): http://crbug.com/128134 - Break the circular dependency
   # without requiring nssckbi to be built as a shared library.
   source_set("nssckbi") {
-    visibility = ":nss"  # This target is internal implementation detail.
+    visibility = [ ":nss" ]  # This target is internal implementation detail.
 
     sources = [
       "nss/lib/ckfw/builtins/anchor.c",
       "nss/lib/ckfw/builtins/bfind.c",
       "nss/lib/ckfw/builtins/binst.c",
       "nss/lib/ckfw/builtins/bobject.c",
       "nss/lib/ckfw/builtins/bsession.c",
       "nss/lib/ckfw/builtins/bslot.c",
       "nss/lib/ckfw/builtins/btoken.c",
       "nss/lib/ckfw/builtins/builtins.h",
@@ skipping 751 matching lines @@
 
     deps = [
       ":nspr",
       "//third_party/sqlite",
     ]
 
     forward_dependent_configs_from = [ ":nspr" ]
   }
 }  # Windows/Mac/iOS.