git cl status: re-use existing ChangeList object.
git cl status: re-use existing ChangeList object.

This way we avoid extra RPC to codereview site.

R=aadb4a11584aa9878242ea5d9e4b7e3429654579@chromium.org
BUG=681704

Change-Id: I81f9ac1b8fe4cfaa95458a5669735168185c47e5
Reviewed-on: https://chromium-review.googlesource.com/430639
Commit-Queue: Andrii Shyshkalov <a30c74fa30536fe7ea81ed6dec202e35e149e1fd@chromium.org>
Reviewed-by: Sergiy Byelozyorov <aadb4a11584aa9878242ea5d9e4b7e3429654579@chromium.org>

CoherentLabs/depot_tools,CoherentLabs/depot_tools