Refactor all gRPC proxy code into a single class.

appengine/swarming/server/bot_archive.py

 # Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Generates the swarming_bot.zip archive for the bot.
 
 Unlike the other source files, this file can be run from ../tools/bot_archive.py
 stand-alone to generate a swarming_bot.zip for local testing so it doesn't
 import anything from the AppEngine SDK.
 
@@ skipping 306 matching lines @@
     'third_party/rsa/rsa/util.py',
     'third_party/rsa/rsa/varblock.py',
     'third_party/six/__init__.py',
     'third_party/uritemplate/__init__.py',
     'utils/__init__.py',
     'utils/auth_server.py',
     'utils/authenticators.py',
     'utils/cacert.pem',
     'utils/file_path.py',
     'utils/fs.py',
+    'utils/grpc_proxy.py',
     'utils/large.py',
     'utils/logging_utils.py',
     'utils/lru.py',
     'utils/net.py',
     'utils/oauth.py',
     'utils/on_error.py',
     'utils/subprocess42.py',
     'utils/threading_utils.py',
     'utils/tools.py',
     'utils/zip_package.py',
@@ skipping 121 matching lines @@
       h.update(str(len(name)))
       h.update(name)
       h.update(str(len(content)))
       h.update(content)
   except IOError:
     logging.warning('Missing expected file. Hash will be invalid.')
   bot_version = h.hexdigest()
   logging.info(
       'get_swarming_bot_version(%s) = %s', sorted(additionals), bot_version)
   return bot_version