XXX test gn format everything

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.
 
 defines = [ "GN_BUILD" ]
 
 static_library("gn_lib") {
   sources = [
     "action_target_generator.cc",
     "action_target_generator.h",
@@ skipping 168 matching lines @@
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
   ]
 }
 
 action("last_commit_position") {
   script = "last_commit_position.py"
 
   # This dependency forces a re-run when the code is synced.
-  inputs = [ "//build/util/LASTCHANGE" ]
+  inputs = [
+    "//build/util/LASTCHANGE",
+  ]
 
   outfile = "$target_gen_dir/last_commit_position.h"
   outputs = [ outfile ]
 
   args = [
     rebase_path("//", root_build_dir),
     rebase_path(outfile, root_build_dir),
     "TOOLS_GN_LAST_COMMIT_POSITION_H_",
   ]
 }
@@ skipping 62 matching lines @@
     "visibility_unittest.cc",
   ]
   deps = [
     ":gn_lib",
     "//base/test:test_support",
     "//testing/gtest",
   ]
 }
 
 executable("generate_test_gn_data") {
-  sources = [ "generate_test_gn_data.cc" ]
-  deps = [ "//base" ]
+  sources = [
+    "generate_test_gn_data.cc",
+  ]
+  deps = [
+    "//base",
+  ]
 }