GitLab

The remapping is no longer needed after
https://chromium-review.googlesource.com/1074750, which guarantees that
session IDs do not collide across restarts of the browser.

This reduces the number of IO operations, makes the sync protocol itself
more robust, and greatly simplifies a code that is believed to be
problematic.

Bug: 823798
Change-Id: I6f9192bdb1c2860136279d918e575748dd4e48af
Reviewed-on: https://chromium-review.googlesource.com/1086944
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565601}