Remove all ReadingList entries on managed account signout.

Remove all ReadingList entries on managed account signout.

Clearing happens after the actual signout, so only local data is deleted.
Also interrupt current distillation on signout as profile may change.

BUG=699590
Review-Url: https://codereview.chromium.org/2745313004
Cr-Commit-Position: refs/heads/master@{#458377}
(cherry picked from commit 85c6bf63ddea1f0a18f2404090acb96f67369ca2)

Review-Url: https://codereview.chromium.org/2770723004 .
Cr-Commit-Position: refs/branch-heads/3029@{#380}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/8e3637fbb0c5adf4a37f36c059a85dccae1b1f40

[Olivier, 2017-03-23 09:07:38]

Description was changed from

==========
Remove all ReadingList entries on managed account signout.

Clearing happens after the actual signout, so only local data is deleted.
Also interrupt current distillation on signout as profile may change.

BUG=699590

Review-Url: https://codereview.chromium.org/2745313004
Cr-Commit-Position: refs/heads/master@{#458377}
(cherry picked from commit 85c6bf63ddea1f0a18f2404090acb96f67369ca2)
==========

to

==========
Remove all ReadingList entries on managed account signout.

Clearing happens after the actual signout, so only local data is deleted.
Also interrupt current distillation on signout as profile may change.

BUG=699590

Review-Url: https://codereview.chromium.org/2745313004
Cr-Commit-Position: refs/heads/master@{#458377}
(cherry picked from commit 85c6bf63ddea1f0a18f2404090acb96f67369ca2)

Review-Url: https://codereview.chromium.org/2770723004 .
Cr-Commit-Position: refs/branch-heads/3029@{#380}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/8e3637fbb0c5adf4a37f36c059a8...
==========

[Olivier, 2017-03-23 09:07:39]

Committed patchset #1 (id:1) manually as
8e3637fbb0c5adf4a37f36c059a85dccae1b1f40.