[Culprit-Finder] Seperate gae related part in cache_decorator and gitile repository to gae_libs/

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 6fee9d78a915bef22231878865acc3b9a74f6bda..3067059156d6851e30ada96e5c8e1007125ecc9b 100644
--- a/appengine/findit/waterfall/pull_changelog_pipeline.py
+++ b/appengine/findit/waterfall/pull_changelog_pipeline.py
@@ -5,14 +5,14 @@
 from common.http_client_appengine import HttpClientAppengine as HttpClient
 from common.pipeline_wrapper import BasePipeline
 from common.pipeline_wrapper import pipeline
-from lib.gitiles.gitiles_repository import GitilesRepository
+from gae_libs.gitiles.cached_gitiles_repository import CachedGitilesRepository
 
 
 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 = GitilesRepository(
+  GIT_REPO = CachedGitilesRepository(
       HttpClient(), 'https://chromium.googlesource.com/chromium/src.git')
 
   # Arguments number differs from overridden method - pylint: disable=W0221