Port cronet_package GYP target to GN

components/cronet/tools/generate_javadoc.py

 #!/usr/bin/env python
 #
 # Copyright 2015 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 fnmatch
 import optparse
 import os
 import sys
@@ skipping 30 matching lines @@
   javadoc_cmd = ['ant', '-Dsource.dir=src', '-Ddoc.dir=' + output_dir,
              '-Doverview=' + overview_file, 'doc']
   stdout = build_utils.CheckOutput(javadoc_cmd, cwd=working_dir)
   if " error: " in stdout or "warning" in stdout:
     build_utils.DeleteDirectory(output_dir)
     raise build_utils.CalledProcessError(working_dir, javadoc_cmd, stdout)
 
 
 def main():
   parser = optparse.OptionParser()
+  build_utils.AddDepfileOption(parser)
   parser.add_option('--output-dir', help='Directory to put javadoc')
   parser.add_option('--input-dir', help='Root of cronet source')
   parser.add_option('--overview-file', help='Path of the overview page')
   parser.add_option('--readme-file', help='Path of the README.md')
 
   options, _ = parser.parse_args()
 
   net_docs.ProcessDocs([options.readme_file], options.input_dir,
                        options.output_dir, extensions=[CronetExtension()])
 
   GenerateJavadoc(options)
 
+  if options.depfile:
+    input_paths = []
+    for root, _, filenames in os.walk(options.input_dir):
+      input_paths.extend(os.path.join(root, f) for f in filenames)
+    build_utils.WriteDepfile(options.depfile,
+                             input_paths + build_utils.GetPythonDependencies())
+
 if __name__ == '__main__':
   sys.exit(main())
-