Change FileArg syntax

build/android/gyp/write_build_config.py

 #!/usr/bin/env python
 #
 # Copyright 2014 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.
 
 """Writes a build_config file.
 
 The build_config file for a target is a json file containing information about
 how to build that target based on the target's dependencies. This includes
 things like: the javac classpath, the list of android resources dependencies,
 etc. It also includes the information needed to create the build_config for
 other targets that depend on that one.
 
 There are several different types of build_configs:
   android_library: An android library containing java code.
   android_resources: A target containing android resources.
 
 Android build scripts should not refer to the build_config directly, and the
 build specification should instead pass information in using the special
 file-arg syntax (see build_utils.py:ExpandFileArgs). That syntax allows passing
 of values in a json dict in a file and looks like this:
-  --python-arg=@(build_config_path:javac:classpath)
+  --python-arg=@FileArg(build_config_path:javac:classpath)
 
 Note: If paths to input files are passed in this way, it is important that:
   1. inputs/deps of the action ensure that the files are available the first
   time the action runs.
   2. Either (a) or (b)
     a. inputs/deps ensure that the action runs whenever one of the files changes
     b. the files are added to the action's depfile
 """
 
 import optparse
@@ skipping 105 matching lines @@
   build_utils.WriteJson(config, options.build_config, only_if_changed=True)
 
   if options.depfile:
     build_utils.WriteDepfile(
         options.depfile,
         all_deps_config_paths + build_utils.GetPythonDependencies())
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))