The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d

commit 3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d
Author: fgorski <fgorski@chromium.org>
Date: Tue Apr 25 16:36:30 2017

[Offline pages] Removing active_request_ from request coordinator

This patch removes active_request_ from RequestCoordinator.
Referring to it when updating state of the database was a source
of error in the past. This is safe to do with a minor tweak to
Offliner interface (mainly cancel callback), because it already
keeps a copy of a pending request.

It turns out that simply keeping an ID of the currently processed
request is enough. This opens us to offlining multiple things in
parallel in future, as we can keep a map of id to offliner.

Relevant offliner implementations and tests are adjusted for this
change.

#fixit This bug is part of Paquete fixit effort.

BUG= 714262 
R=chili@chromium.org,petewil@chromium.org

Review-Url: https://codereview.chromium.org/2836863002
Cr-Commit-Position: refs/heads/master@{#467013}

[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/chrome/browser/android/offline_pages/background_loader_offliner.cc
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/chrome/browser/android/offline_pages/background_loader_offliner.h
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/chrome/browser/android/offline_pages/background_loader_offliner_unittest.cc
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/chrome/browser/android/offline_pages/prerendering_offliner.cc
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/chrome/browser/android/offline_pages/prerendering_offliner.h
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/chrome/browser/android/offline_pages/prerendering_offliner_unittest.cc
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/components/offline_pages/core/background/offliner.h
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/components/offline_pages/core/background/offliner_stub.cc
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/components/offline_pages/core/background/offliner_stub.h
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/components/offline_pages/core/background/request_coordinator.cc
[modify] https://crrev.com/3d9408b382d593aa59f01dc5cb9ae8f0bc564e1d/components/offline_pages/core/background/request_coordinator.h