[AF Sync] React to initial merge in wallet metadata sync bridge

This CL finally implements initial merge of sync data. With this CL, the
bridge should be complete.

Unit-tests are not part of the CL as I want to first get the bridge into
state to pass integration tests (fix all issues on the way) and then
only write unit-tests to test the final behavior.

Bug: 853688
Change-Id: Ide5eab01b2408e15792b6046b67c47caa3256f90
Reviewed-on: https://chromium-review.googlesource.com/c/1406717
Commit-Queue: Jan Krcal <jkrcal@chromium.org>
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622317}
2 files changed