GN + Android: support standalone .dex.jar output of Android libraries.

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
@@ skipping 195 matching lines @@
     config['resources'] = {}
     config['resources']['dependency_zips'] = [
         c['resources_zip'] for c in all_resources_deps]
     config['resources']['extra_package_names'] = []
 
   if options.type == 'android_apk':
     config['resources']['extra_package_names'] = [
         c['package_name'] for c in all_resources_deps if 'package_name' in c]
 
 
-  if options.type == 'android_apk':
-    config['apk_dex'] = {}
-    dex_config = config['apk_dex']
+  # Dependencies for the final dex file of an apk or the standalone .dex.jar
+  # output of a library.
+  if options.type == 'android_apk' or (options.type == "java_library"
+                                       and options.supports_android):
+    config['final_dex'] = {}
+    dex_config = config['final_dex']
     # TODO(cjhopman): proguard version
     dex_deps_files = [c['dex_path'] for c in all_library_deps]
     dex_config['dependency_dex_files'] = dex_deps_files
 
+  if options.type == 'android_apk':
     config['dist_jar'] = {
       'dependency_jars': [
         c['jar_path'] for c in all_library_deps
       ]
     }
 
     library_paths = []
     java_libraries_list = []
     if options.native_libs:
       libraries = build_utils.ParseGypList(options.native_libs)
@@ skipping 19 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:]))