GitLab

According to some investigation, "Files: list" should be faster than
"Changes: list". We can use this because we extract change list id from
"About: get" API.

BUG=287602
TEST=Ran unit_tests and tested manually.

WIP

Review URL: https://chromiumcodereview.appspot.com/23958006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222016 0039d316-1c4b-4281-b951-d872f2087c98