Partially evert "Remove the support for isolate_dependency_*."
Partially evert "Remove the support for isolate_dependency_*."

This reverts isolate_format.py in commit e6dac5886ded06698ed64691f5665a1b225b8e67.

There's a change that needs to be done inside the chromium tree before this can
be rolled in and I suspect it'll take a few days for this change to be
completed. Until this change is done all the canaries are red.

Temporarily revert this change until the fix in the chromium tree is completed,
so we keep a green canary.

TBR=vadimsh@chromium.org
BUG=

Review URL: https://codereview.appspot.com/155750043

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py