libweave: base::Value refactor in src/config.cc

In particular base::DictionaryValue::Remove* will be deprecated after
libchrome r920000 uprev.

BUG=chromium:1099111, b:198993705
TEST=FEATURES=test emerge-hatch libweave

Change-Id: Ib9ac97a1f1e8922b75a95949b74ff8b1cbca24ad
Reviewed-on: https://chromium-review.googlesource.com/c/weave/libweave/+/3143574
Tested-by: Grace Cham <hscham@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Commit-Queue: Grace Cham <hscham@chromium.org>
1 file changed