Add "." accessors to GN.

tools/gn/BUILD.gn

 # Copyright (c) 2013 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.
 
 gyp_file = "gn.gyp"
 external = true
 
 # Not defined when doing a GYP build, this lets the code key off of GN-specific
 # features (the last change target). This can be removed when the last change
 # target is supported by the GN->GYP converter (see is_gyp conditional for that
@@ skipping 180 matching lines @@
     "gyp_action_target_writer_unittest.cc",
     "gyp_binary_target_writer_unittest.cc",
     "input_conversion_unittest.cc",
     "label_unittest.cc",
     "loader_unittest.cc",
     "ninja_action_target_writer_unittest.cc",
     "ninja_binary_target_writer_unittest.cc",
     "ninja_copy_target_writer_unittest.cc",
     "ninja_helper_unittest.cc",
     "operators_unittest.cc",
+    "parse_tree_unittest.cc",
     "parser_unittest.cc",
     "path_output_unittest.cc",
     "pattern_unittest.cc",
     "scope_per_file_provider_unittest.cc",
     "scope_unittest.cc",
     "source_dir_unittest.cc",
     "string_utils_unittest.cc",
     "target_generator_unittest.cc",
     "target_unittest.cc",
     "test_with_scope.cc",
     "test_with_scope.h",
     "tokenizer_unittest.cc",
   ]
   deps = [
     ":gn_lib",
     "//base/test:run_all_unittests",
     "//base/test:test_support_base",
     "//testing/gtest",
   ]
 }
 
 executable("generate_test_gn_data") {
   sources = [ "generate_test_gn_data.cc" ]
   deps = [ "//base" ]
 }