GN: Format more gn files

sdk/lib/rules.gni

 # Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 default_dart_root = rebase_path("../..")
 
 # This build rule will copy the source for one Dart SDK library.
 #
 # Required arguments:
 #   sdk_lib_name
@@ skipping 13 matching lines @@
   if (defined(invoker.dart_root)) {
     dart_root = rebase_path(invoker.dart_root)
   } else {
     dart_root = default_dart_root
   }
   if (defined(invoker.destination)) {
     destination = invoker.destination
   } else {
     destination = "$root_gen_dir/dart_sdk"
   }
-  dart_sdk_sdk_lib_path =
-      rebase_path("sdk/lib", "", dart_root)
+  dart_sdk_sdk_lib_path = rebase_path("sdk/lib", "", dart_root)
   dart_sdk_tools_gypi_to_gn_path =
       rebase_path("tools/gypi_to_gn.py", "", dart_root)
+
   # The name of the SDK library being copied.
   lib_name = invoker.sdk_lib_name
+
   # The path to the libraries source directory.
   lib_path = rebase_path(lib_name, "", dart_sdk_sdk_lib_path)
+
   # The path to the sources gypi.
   lib_sources_gypi = lib_name + "_sources.gypi"
+
   # Get the contents of the gypi file.
   sdk_lib_sources_gypi =
       exec_script(dart_sdk_tools_gypi_to_gn_path,
-                  [rebase_path(lib_sources_gypi, "", lib_path)],
+                  [ rebase_path(lib_sources_gypi, "", lib_path) ],
                   "scope",
-                  [rebase_path(lib_sources_gypi, "", lib_path)])
+                  [ rebase_path(lib_sources_gypi, "", lib_path) ])
   copy(target_name) {
     sources = rebase_path(sdk_lib_sources_gypi.sources, "", lib_path)
-    outputs = [ "$destination/$lib_name/{{source_file_part}}" ]
+    outputs = [
+      "$destination/$lib_name/{{source_file_part}}",
+    ]
   }
 }