Convert GN visibility variables to lists.

build/secondary/tools/grit/grit_rule.gni

 # 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.
 
 # Instantiate grit. This will produce a script target to run grit, and a
 # static library that compiles the .cc files.
 #
 # Parameters
 #
 #   source (required)
@@ skipping 240 matching lines @@
   assert_files_flags += [
     "--assert-file-list=" + rebase_path(asserted_list_file, root_build_dir),
   ]
   grit_outputs = get_path_info(
       rebase_path(invoker.outputs, ".", output_dir),
       "abspath")
 
   # The config and the action below get this visibility son only the generated
   # source set can depend on them. The variable "target_name" will get
   # overwritten inside the inner classes so we need to compute it here.
-  target_visibility = ":$target_name"
+  target_visibility = [ ":$target_name" ]
 
   # The current grit setup makes an file in $output_dir/grit/foo.h that
   # the source code expects to include via "grit/foo.h". It would be nice to
   # change this to including absolute paths relative to the root gen directory
   # (like "mycomponent/foo.h"). This config sets up the include path.
   grit_config = target_name + "_grit_config"
   config(grit_config) {
     if (!defined(invoker.use_qualified_include) ||
         !invoker.use_qualified_include) {
       include_dirs = [ output_dir ]
@@ skipping 22 matching lines @@
 
     # Add extra defines with -D flags.
     if (defined(invoker.defines)) {
       foreach (i, invoker.defines) {
         args += [ "-D", i ]
       }
     }
 
     args += grit_flags + assert_files_flags
 
-    visibility = target_visibility
+    if (defined(invoker.visibility)) {
+      # This needs to include both what the invoker specified (since they
+      # probably include generated headers from this target), as well as the
+      # generated source set (since there's no guarantee that the visibility
+      # specified by the invoker includes our target).
+      #
+      # Only define visibility at all if the invoker specified it. Otherwise,
+      # we want to keep the public "no visibility specified" default.
+      visibility = target_visibility + invoker.visibility
+    }
 
     deps = [ "//tools/grit:grit_sources" ]
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
   }
 
   # This is the thing that people actually link with, it must be named the
   # same as the argument the template was invoked with.
   source_set(target_name) {
     # Since we generate a file, we need to be run before the targets that
     # depend on us.
     sources = grit_outputs
 
     # Deps set on the template invocation will go on the grit script running
     # target rather than this library.
     deps = [ ":$grit_custom_target" ]
     direct_dependent_configs = [ ":$grit_config" ]
 
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     output_name = grit_output_name
   }
 }