First CL up @ https://codereview.chromium.org/2042383004/

Note: pinged https://codereview.chromium.org/1414793009/ where SequencedTaskRunner from unsequenced tasks was intentionally implemented in case people on that thread care (it did make sense back then but see design doc above to see why I've changed my mind).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9f79bb50c6a36522eac9e0fb327c644ffb09c405

commit 9f79bb50c6a36522eac9e0fb327c644ffb09c405
Author: gab <gab@chromium.org>
Date: Wed Jun 22 22:11:38 2016

WeakPtr requires SequencedTaskRunner, correct interface in blimp_client_session.cc

The caller is already using a SequencedTaskRunner but it's incorrect for this
interface to allow a plain TaskRunner per its use of WeakPtr.

BUG= 618043 

Review-Url: https://codereview.chromium.org/2085173003
Cr-Commit-Position: refs/heads/master@{#401431}

[modify] https://crrev.com/9f79bb50c6a36522eac9e0fb327c644ffb09c405/blimp/client/session/blimp_client_session.cc

Renaming per conclusion of discussion @ https://groups.google.com/a/chromium.org/d/topic/chromium-dev/cd9hldEhIEc/discussion

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b

commit 41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b
Author: gab <gab@chromium.org>
Date: Thu Jul 28 18:38:07 2016

Revert "Allow SequencedTaskRunnerHandle::Get() while running unsequenced tasks."

This is effectively a manual revert of 5d315e4b4a7cdef34b0c1e863353d03a30781217.

Per the outcome of the discussion on  http://crbug.com/618043  and associated doc/chromium-dev discussion.

BUG= 618043 

Review-Url: https://codereview.chromium.org/2177373005
Cr-Commit-Position: refs/heads/master@{#408440}

[modify] https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b/base/threading/sequenced_task_runner_handle.cc
[modify] https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b/base/threading/sequenced_task_runner_handle.h
[modify] https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b/base/threading/sequenced_task_runner_handle_unittest.cc
[modify] https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b/base/threading/sequenced_worker_pool.cc
[modify] https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b/base/threading/sequenced_worker_pool.h
[modify] https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b/base/threading/sequenced_worker_pool_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2

commit 33a2c419dbc05f970bc5de86ad7f3d3919a93bc2
Author: gab <gab@chromium.org>
Date: Thu Jul 28 19:05:07 2016

Revert of Revert "Allow SequencedTaskRunnerHandle::Get() while running unsequenced tasks." (patchset #2 id:40001 of https://codereview.chromium.org/2177373005/ )

Reason for revert:
Actually oops forgot this wasn't supposed to land until this blocker is resolved : https://bugs.chromium.org/p/chromium/issues/detail?id=618043#c5

Original issue's description:
> Revert "Allow SequencedTaskRunnerHandle::Get() while running unsequenced tasks."
>
> This is effectively a manual revert of 5d315e4b4a7cdef34b0c1e863353d03a30781217.
>
> Per the outcome of the discussion on  http://crbug.com/618043  and associated doc/chromium-dev discussion.
>
> BUG= 618043 
>
> Committed: https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b
> Cr-Commit-Position: refs/heads/master@{#408440}

TBR=danakj@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 618043 

Review-Url: https://codereview.chromium.org/2190073002
Cr-Commit-Position: refs/heads/master@{#408448}

[modify] https://crrev.com/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2/base/threading/sequenced_task_runner_handle.cc
[modify] https://crrev.com/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2/base/threading/sequenced_task_runner_handle.h
[modify] https://crrev.com/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2/base/threading/sequenced_task_runner_handle_unittest.cc
[modify] https://crrev.com/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2/base/threading/sequenced_worker_pool.cc
[modify] https://crrev.com/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2/base/threading/sequenced_worker_pool.h
[modify] https://crrev.com/33a2c419dbc05f970bc5de86ad7f3d3919a93bc2/base/threading/sequenced_worker_pool_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0

commit a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0
Author: gab <gab@chromium.org>
Date: Mon Aug 01 17:29:50 2016

Revert "Allow SequencedTaskRunnerHandle::Get() while running unsequenced tasks."

This is effectively a manual revert of 5d315e4b4a7cdef34b0c1e863353d03a30781217.

Per the outcome of the discussion on  http://crbug.com/618043  and associated doc/chromium-dev discussion.

BUG= 618043 

Committed: https://crrev.com/41339c7ae8458dd500d1be0e9d4b8da6d8c4c33b
Review-Url: https://codereview.chromium.org/2177373005
Cr-Original-Commit-Position: refs/heads/master@{#408440}
Cr-Commit-Position: refs/heads/master@{#408992}

[modify] https://crrev.com/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0/base/threading/sequenced_task_runner_handle.cc
[modify] https://crrev.com/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0/base/threading/sequenced_task_runner_handle.h
[modify] https://crrev.com/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0/base/threading/sequenced_task_runner_handle_unittest.cc
[modify] https://crrev.com/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0/base/threading/sequenced_worker_pool.cc
[modify] https://crrev.com/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0/base/threading/sequenced_worker_pool.h
[modify] https://crrev.com/a414e99dbf38480dc4ac6e69368c2b13b0b6a0f0/base/threading/sequenced_worker_pool_unittest.cc