Reorder protobuf compiler command line arguments.

tools/protoc_wrapper/protoc_wrapper.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """
 A simple wrapper for protoc.
 Script for //third_party/protobuf/proto_library.gni .
 Features:
 - Inserts #include for extra header automatically.
@@ skipping 78 matching lines @@
                       help="Standard C++ generator options.")
   parser.add_argument("--include",
                       help="Name of include to insert into generated headers.")
 
   parser.add_argument("protos", nargs="+",
                       help="Input protobuf definition file(s).")
 
   options = parser.parse_args()
 
   proto_dir = os.path.relpath(options.proto_in_dir)
-  protoc_cmd = [
-    os.path.realpath(options.protoc),
-    "--proto_path", proto_dir
-  ]
+  protoc_cmd = [os.path.realpath(options.protoc)]
 
   protos = options.protos
   headers = []
   VerifyProtoNames(protos)
 
+  if options.py_out_dir:
+    protoc_cmd += ["--python_out", options.py_out_dir]
+
   if options.cc_out_dir:
     cc_out_dir = options.cc_out_dir
     cc_options = FormatGeneratorOptions(options.cc_options)
     protoc_cmd += ["--cpp_out", cc_options + cc_out_dir]
     for filename in protos:
       stripped_name = StripProtoExtension(filename)
       headers.append(os.path.join(cc_out_dir, stripped_name + ".pb.h"))
 
-  if options.py_out_dir:
-    protoc_cmd += ["--python_out", options.py_out_dir]
-
   if options.plugin_out_dir:
     plugin_options = FormatGeneratorOptions(options.plugin_options)
     protoc_cmd += [
       "--plugin", "protoc-gen-plugin=" + os.path.relpath(options.plugin),
       "--plugin_out", plugin_options + options.plugin_out_dir
     ]
 
+  protoc_cmd += ["--proto_path", proto_dir]
   protoc_cmd += [os.path.join(proto_dir, name) for name in protos]
   ret = subprocess.call(protoc_cmd)
   if ret != 0:
     raise RuntimeError("Protoc has returned non-zero status: "
                        "{0} .".format(ret))
 
   if options.include:
     WriteIncludes(headers, options.include)
 
 
 if __name__ == "__main__":
   try:
     main(sys.argv)
   except RuntimeError as e:
     print(e, file=sys.stderr)
     sys.exit(1)