Add methods for scheduling creation of missing SourceChange events

With new class ParentWalker that traverse from parents to children.
It includes optional attribute parentKey that specify that only
direct children of this parent commit should be traversed.

Solves: Jira GER-1545
Change-Id: I53afe4b07ce0a3211c7aa675ba4beeddad073530
5 files changed
tree: daf42bea9fc683ff8a4573828361ebe0cd3deb4c
  1. src/
  2. BUILD
  3. external_plugin_deps.bzl