tree 7c330b76c8b7a21368d5405fa292b5fbd4355fe9
parent 89bd357a5e4cfb88b478f6a0c3d898f5e74a826b
author Gabriel Schine <thatguy@google.com> 1545868192 -0800
committer Gabriel Schine <thatguy@google.com> 1547166003 -0800

[sessionmgr][refactor] Implement Ledger-backed storage.

This stores only those fields in StoryModel in use right now:
runtime_state and visibility_state. They are stored in a device-local
prefix of the page.

Note that this will replace most if not all of StoryStorage entirely
once all of its data has been migrated into StoryModel.

TEST=ledger_story_model_storage_unittest
MF-152 #comment [sessionmgr][refactor] Implement Ledger-backed storage.

Change-Id: Ia96e581aaa633abb3b9c90e907be18dac1772e75