Use gn_helpers to deserialize GN lists.

build/android/gyp/util/build_utils.py

 # Copyright 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.
 
 import ast
 import contextlib
 import fnmatch
 import json
 import os
 import pipes
@@ skipping 59 matching lines @@
 
 
 def FindInDirectories(directories, filename_filter):
   all_files = []
   for directory in directories:
     all_files.extend(FindInDirectory(directory, filename_filter))
   return all_files
 
 
 def ParseGnList(gn_string):
+  # TODO(brettw) bug 573132: This doesn't handle GN escaping properly, so any
+  # weird characters like $ or \ in the strings will be corrupted.
+  #
+  # The code should import build/gn_helpers.py and then do:
+  #   parser = gn_helpers.GNValueParser(gn_string)
+  #   return return parser.ParseList()
+  # As of this writing, though, there is a CastShell build script that sends
+  # JSON through this function, and using correct GN parsing corrupts that.
+  #
+  # We need to be consistent about passing either JSON or GN lists through
+  # this function.
   return ast.literal_eval(gn_string)
 
 
 def ParseGypList(gyp_string):
   # The ninja generator doesn't support $ in strings, so use ## to
   # represent $.
   # TODO(cjhopman): Remove when
   # https://code.google.com/p/gyp/issues/detail?id=327
   # is addressed.
   gyp_string = gyp_string.replace('##', '$')
@@ skipping 386 matching lines @@
 
   md5_check.CallAndRecordIfStale(
       on_stale_md5,
       record_path=record_path,
       input_paths=input_paths,
       input_strings=input_strings,
       output_paths=output_paths,
       force=force,
       pass_changes=True)