thermald: update for libchrome uprev to r680000

- Use base::RepeatingTimer
- Use base::NumberToString
- Use base::JSONReader::ReadDeprecated, since Read will be a new API.

BUG=chromium:1054279
TEST=CQ

Change-Id: I395e48bec4a9c4840fcb0196ee95f81fb896db77
Reviewed-on: https://chrome-internal-review.googlesource.com/c/chromeos/thermald/+/2829303
Reviewed-by: Qijiang Fan <fqj@google.com>
Commit-Queue: Qijiang Fan <fqj@google.com>
Tested-by: Qijiang Fan <fqj@google.com>
7 files changed