Use non-system protobuf in third_party/dom_distiller_js/protoc_plugins

third_party/dom_distiller_js/protoc_plugins/util/plugin_protos.py

 # Copyright 2016 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.
 
 """
 Provides simple state-less wrappers of the proto types used by plugins.
 
 See https://developers.google.com/protocol-buffers/docs/reference/cpp/google.protobuf.descriptor.pb
 and https://developers.google.com/protocol-buffers/docs/reference/cpp/google.protobuf.compiler.plugin.pb
 """
 
 import os
 import sys
 
+SCRIPT_DIR = os.path.dirname(__file__)
+SRC_DIR = os.path.abspath(os.path.join(SCRIPT_DIR, '..', '..', '..', '..'))
+
+sys.path.insert(
+    1, os.path.join(SRC_DIR, 'third_party', 'protobuf', 'python'))
+sys.path.insert(
+    1, os.path.join(SRC_DIR, 'third_party', 'protobuf', 'third_party', 'six'))
 from google.protobuf.descriptor_pb2 import FieldDescriptorProto
 
 import plugin
 import types
 
 sys.path.insert(
-    1, os.path.join(os.path.dirname(__file__), '..', '..',
-                    'dist', 'python'))
+    1, os.path.join(SRC_DIR, 'third_party', 'dom_distiller_js', 'dist', 'python'))
 import plugin_pb2
 
 
 class PluginRequest(object):
   def __init__(self, proto):
     self.proto = proto
 
   def GetArgs(self):
     return dict((v.split('=') for v in self.proto.parameter.split(',')))
 
@@ skipping 242 matching lines @@
   def GetName(self):
     return self.proto.name
 
   def GetValue(self):
     return self.proto.number
 
   def CheckSupported(self):
     if self.proto.HasField('options'):
       return 'Enum value options are not supported: {} {}'.format(
           self.proto.name, self.proto.value)