[Culprit-Finder] Refactor GitilesRepostory to make http_client required argument.

appengine/findit/waterfall/send_notification_for_culprit_pipeline.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.
 
 from datetime import datetime
 import logging
 import textwrap
 
 from google.appengine.ext import ndb
 
@@ skipping 75 matching lines @@
   _UpdateNotificationStatus(repo_name, revision,
                             status.COMPLETED if sent else status.ERROR)
   return sent
 
 
 def _GetCulpritInfo(repo_name, revision):
   """Returns commit position/time and code-review url of the given revision."""
   # TODO(stgao): get repo url at runtime based on the given repo name.
   # unused arg - pylint: disable=W0612,W0613
   repo = GitilesRepository(
-      'https://chromium.googlesource.com/chromium/src.git', HttpClient())
+      HttpClient(), 'https://chromium.googlesource.com/chromium/src.git')
   change_log = repo.GetChangeLog(revision)
   return change_log.commit_position, change_log.code_review_url
 
 
 def _WithinNotificationTimeLimit(build_end_time, latency_limit_minutes):
   """Returns True if it is still in time to send notification."""
   latency_seconds = (time_util.GetUTCNow() - build_end_time).total_seconds()
   return latency_seconds <= latency_limit_minutes * 60
 
 
@@ skipping 25 matching lines @@
         'within_time_limit': within_time_limit
     }
 
     if not _ShouldSendNotification(
       master_name, builder_name, build_number, repo_name,
       revision, commit_position, build_num_threshold, additional_criteria,
       send_notification_right_now):
       return False
     return _SendNotificationForCulprit(
         repo_name, revision, commit_position, code_review_url)