chromeos-dbus-bindings: Generate Interface Generate an interface class that contains pure-virtual methods for each method supported by the interface. Also generate a controller that registers these methods with an exported DBus interface. BUG=chromium:404505 TEST=New unit test Change-Id: Ib9eacdd822982e6e992d10fc21a4eec804489b45 Reviewed-on: https://chromium-review.googlesource.com/218749 Reviewed-by: Mike Frysinger <[email protected]> Reviewed-by: Alex Vakulenko <[email protected]> Commit-Queue: Paul Stewart <[email protected]> Tested-by: Paul Stewart <[email protected]>