Use gn_helpers to [se]serialize GN lists.

build/android/gyp/util/build_utils.py

Index: build/android/gyp/util/build_utils.py
diff --git a/build/android/gyp/util/build_utils.py b/build/android/gyp/util/build_utils.py
index c601e06d7157fd97855749a8ecd781c22aac590f..beb7bcfbf1e9c8cbd0a5ef85dd5e6083b588b04f 100644
--- a/build/android/gyp/util/build_utils.py
+++ b/build/android/gyp/util/build_utils.py
@@ -22,6 +22,10 @@ import md5_check  # pylint: disable=relative-import
 sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir, os.pardir))
 from pylib.constants import host_paths
 
+sys.path.append(os.path.join(os.path.dirname(__file__),
+                             os.pardir, os.pardir, os.pardir))
+import gn_helpers
+
 COLORAMA_ROOT = os.path.join(host_paths.DIR_SOURCE_ROOT,
                              'third_party', 'colorama', 'src')
 # aapt should ignore OWNERS files in addition the default ignore pattern.
@@ -77,18 +81,8 @@ def FindInDirectories(directories, filename_filter):
 
 
 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)
+  parser = gn_helpers.GNValueParser(gn_string)
+  return parser.ParseList()
 
 
 def ParseGypList(gyp_string):