GitLab

Prior to this patch, the two existing functions to build GUID-keyed maps
were heavily coupled and there were fragile underlying assumptions that
made it work (e.g. there were potentially entries in
|guid_to_remote_node_map_| that didn't actually match any local GUID).

Instead, let's centralize the matching logic into one single function,
and adopt a unified map to represent the matches. This simplifies the
code and enforces more strict invariants without the need for DCHECKs.

Bug: 978430
Change-Id: Ieea0db8d43376e204b793dcc64b2dc84d521b289
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1929216
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: Mohamed Amir Yosef <mamir@chromium.org>
Cr-Commit-Position: refs/heads/master@{#718580}