Convert GN visibility to lists.

Source/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("config.gni")
 if (is_clang) {
   import("//build/config/clang/clang.gni")
 }
 
-visibility = "//third_party/WebKit/*"
+visibility = [ "//third_party/WebKit/*" ]
 
 # features ---------------------------------------------------------------------
 
 config("features") {
   defines = feature_defines_list
 }
 
 # inside_blink -----------------------------------------------------------------
 
 config("inside_blink") {
@@ skipping 50 matching lines @@
 
 # The follow configs apply to all targets except for unit tests, which rely on
 # static initializers.
 config("non_test_config") {
   cflags = []
 
   if (is_clang) {
     cflags += [ "-Wglobal-constructors" ]
   }
 }