[Findit] Factoring the gitiles (etc) stuff out into its own directory

appengine/findit/waterfall/pull_changelog_pipeline.py

Index: appengine/findit/waterfall/pull_changelog_pipeline.py
diff --git a/appengine/findit/waterfall/pull_changelog_pipeline.py b/appengine/findit/waterfall/pull_changelog_pipeline.py
index eb40fb2a0ca912e3d22ec3ad1b730f9daa55f507..3519868e36dee2ad1fc201071f48dc77c0d1ea66 100644
--- a/appengine/findit/waterfall/pull_changelog_pipeline.py
+++ b/appengine/findit/waterfall/pull_changelog_pipeline.py
@@ -2,17 +2,17 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-from common.git_repository import GitRepository
 from common.http_client_appengine import HttpClientAppengine as HttpClient
-from common.pipeline_wrapper import pipeline
 from common.pipeline_wrapper import BasePipeline
+from common.pipeline_wrapper import pipeline
+from lib.gitiles.gitiles_repository import GitilesRepository
 
 
 class PullChangelogPipeline(BasePipeline):
   """A pipeline to pull change log of CLs."""
 
   # TODO: for files in dependencies(blink, v8, skia, etc), use blame first.
-  GIT_REPO = GitRepository(
+  GIT_REPO = GitilesRepository(
       'https://chromium.googlesource.com/chromium/src.git', HttpClient())
 
   # Arguments number differs from overridden method - pylint: disable=W0221