The executor needs to accumnulate more_cc, not overwrite them.

Bug: 786386
Change-Id: Iadfe836ae9623f1b66d2db8209d347b5e61ccae8
Reviewed-on: https://chromium-review.googlesource.com/784553Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>