Implement main blink target in GN.

Source/bindings/scripts/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("//third_party/WebKit/Source/bindings/bindings.gni")
 import("//third_party/WebKit/Source/bindings/scripts/scripts.gni")
 import("//third_party/WebKit/Source/bindings/templates/templates.gni")
 
+visibility = "//third_party/WebKit/*"
+
 # A separate pre-caching step is *not required* to use lex/parse table
 # caching in PLY, as the caches are concurrency-safe.
 # However, pre-caching ensures that all compiler processes use the cached
 # files (hence maximizing speed), instead of early processes building the
 # tables themselves (as they've not yet been written when they start).
 #
 # GYP version: scripts.gyp:cached_lex_yacc_tables
 action("cached_lex_yacc_tables") {
   script = "blink_idl_parser.py"
 
@@ skipping 18 matching lines @@
     code_generator_template_files
   # Dummy file to track dependency.
   stamp_file = "$bindings_scripts_output_dir/cached_jinja_templates.stamp"
   outputs = [ stamp_file ]
 
   args = [
     rebase_path(bindings_scripts_output_dir, root_build_dir),
     rebase_path(stamp_file, root_build_dir),
   ]
 }