Sync: local data verification for Android tests
This CL dramatically improves the ability to verify local Sync data in
Java Android tests. This is done by plumbing through the
ProfileSyncService's GetAllNodes method through JNI.
This new util will also allow for the server-side modification and
deletion of Sync entities in a future CL.
An older version of local data verification
(relying only on entity counts) has been removed.
BUG=365774
Review URL: https://codereview.chromium.org/
1127233008
Cr-Commit-Position: refs/heads/master@{#330842}