cbuildbot: Add '_site_values' to cbuildbot SiteConfig.
Add a new dictionary to the SiteConfig class to aid in
specifying and accessing site-specific constants.
BUG=chromium:497281
TEST=Tested with unittests.
Change-Id: If2291882154665327058ef40e1170a6ca1ec3b68
Reviewed-on: https://chromium-review.googlesource.com/282146
Reviewed-by: Matthew Sartori <msartori@chromium.org>
Commit-Queue: Matthew Sartori <msartori@chromium.org>
Tested-by: Matthew Sartori <msartori@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
3 files changed
