Implement main blink target in GN.

Source/bindings/scripts/scripts.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.
 
 import("//third_party/WebKit/Source/bindings/core/v8/generated.gni")
 import("//third_party/WebKit/Source/bindings/modules/idl.gni")
 import("//third_party/WebKit/Source/bindings/modules/modules.gni")
 
 bindings_scripts_dir = get_path_info(".", "abspath")
 bindings_scripts_output_dir = "$root_gen_dir/blink/bindings/scripts"
@@ skipping 17 matching lines @@
 #   sources_generated = list of generated IDL files to pass as inputs
 #   component_dir = name if subdirectory (one word, no slashes) of component.
 #   output_file = pickle file to write
 #
 # FIXME: Note the static/generated split is for consistency with GYP. This
 # split is not necessary in the GN build and could be combined into a single
 # "sources".
 template("compute_interfaces_info_individual") {
   action(target_name) {
     script = "$bindings_scripts_dir/compute_interfaces_info_individual.py"
+    if (defined(invoker.visibility)) {
+      visibility = invoker.visibility
+    }
 
     # Save static list to temp file to avoid blowing out command-line length
     # limit.
     file_list = "$target_gen_dir/${target_name}_file_list.txt"
     write_file(file_list, rebase_path(invoker.sources_static, root_build_dir))
 
     source_prereqs = [
       "$bindings_scripts_dir/utilities.py",
       file_list,
     ] + invoker.sources_static + invoker.sources_generated
@@ skipping 142 matching lines @@
     outputs = invoker.outputs
 
     args = [
       invoker.component_dir,
       rebase_path(idl_files_list, root_build_dir),
       "--",
     ]
     args += rebase_path(invoker.outputs, root_build_dir)
   }
 }