Allow passing WeakPtr across threads without AllowCrossThreadAccess()

Allow passing WeakPtr across threads without AllowCrossThreadAccess()

This removes AllowCrossThreadAccess() for WeakPtr and
adds CrossThreadCopier for WeakPtr instead.

This CL doesn't introduce crossThreadWeakPtr(), because:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests. Therefore, annotations like
  AllowCrossThreadAccess()/crossThreadWeakPtr() is not so essential in
  catching errors.
- There is no CrossThreadWeakPtr, so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
Committed: https://crrev.com/e656f4c55f88ea32473335e17d6fc2065f119ef2
Cr-Commit-Position: refs/heads/master@{#394154}

[hiroshige, 2016-04-22 13:57:38]

The CQ bit was checked by hiroshige@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-04-22 13:57:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1909353003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1909353003/1

[hiroshige, 2016-04-22 14:10:10]

Description was changed from

==========
Mark AllowCrossThreadCopier() + WeakPtr

BUG=
==========

to

==========
Mark AllowCrossThreadCopier() + WeakPtr

BUG=
==========

[commit-bot: I haz the power, 2016-04-22 15:28:22]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-22 15:28:23]

Dry run: This issue passed the CQ dry run.

[hiroshige, 2016-04-27 06:52:02]

The CQ bit was checked by hiroshige@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-04-27 06:52:11]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1909353003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1909353003/20001

[commit-bot: I haz the power, 2016-04-27 08:13:28]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-27 08:13:29]

Dry run: This issue passed the CQ dry run.

[hiroshige, 2016-04-27 09:27:25]

The CQ bit was checked by hiroshige@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-04-27 09:28:01]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1909353003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1909353003/40001

[commit-bot: I haz the power, 2016-04-27 13:08:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-27 13:08:47]

Dry run: This issue passed the CQ dry run.

[hiroshige, 2016-05-17 06:44:34]

The CQ bit was checked by hiroshige@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-05-17 06:44:48]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1909353003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1909353003/60001

[hiroshige, 2016-05-17 07:41:33]

Description was changed from

==========
Mark AllowCrossThreadCopier() + WeakPtr

BUG=
==========

to

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

As a step to remove AllowCrossThreadAccess().

Alternatively, we could introduce crossThreadWeakPtr() as an annotation, but:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests.
- There is no CrossThreadWeakPtr so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
==========

[hiroshige, 2016-05-17 07:41:33]

hiroshige@chromium.org changed reviewers:
+ haraken@chromium.org, kinuko@chromium.org, tzik@chromium.org

[commit-bot: I haz the power, 2016-05-17 08:27:12]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-05-17 08:27:13]

Dry run: This issue passed the CQ dry run.

[hiroshige, 2016-05-17 08:57:45]

Description was changed from

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

As a step to remove AllowCrossThreadAccess().

Alternatively, we could introduce crossThreadWeakPtr() as an annotation, but:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests.
- There is no CrossThreadWeakPtr so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
==========

to

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

This removes AllowCrossThreadAccess() for WeakPtr and
adds CrossThreadCopier for WeakPtr instead.

This CL doesn't introduce crossThreadWeakPtr(), because:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests. Therefore, annotations like
  AllowCrossThreadAccess()/crossThreadWeakPtr() is not so essential in
  catching errors.
- There is no CrossThreadWeakPtr, so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
==========

[hiroshige, 2016-05-17 08:57:59]

PTAL.

[haraken, 2016-05-17 08:59:18]

LGTM

[kinuko, 2016-05-17 10:04:02]

lgtm/2

[tzik, 2016-05-17 11:16:15]

lgtm

[hiroshige, 2016-05-17 17:23:28]

The CQ bit was checked by hiroshige@chromium.org

[commit-bot: I haz the power, 2016-05-17 17:23:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1909353003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1909353003/60001

[commit-bot: I haz the power, 2016-05-17 17:27:13]

Description was changed from

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

This removes AllowCrossThreadAccess() for WeakPtr and
adds CrossThreadCopier for WeakPtr instead.

This CL doesn't introduce crossThreadWeakPtr(), because:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests. Therefore, annotations like
  AllowCrossThreadAccess()/crossThreadWeakPtr() is not so essential in
  catching errors.
- There is no CrossThreadWeakPtr, so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
==========

to

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

This removes AllowCrossThreadAccess() for WeakPtr and
adds CrossThreadCopier for WeakPtr instead.

This CL doesn't introduce crossThreadWeakPtr(), because:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests. Therefore, annotations like
  AllowCrossThreadAccess()/crossThreadWeakPtr() is not so essential in
  catching errors.
- There is no CrossThreadWeakPtr, so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
==========

[commit-bot: I haz the power, 2016-05-17 17:27:14]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-05-17 17:28:58]

Description was changed from

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

This removes AllowCrossThreadAccess() for WeakPtr and
adds CrossThreadCopier for WeakPtr instead.

This CL doesn't introduce crossThreadWeakPtr(), because:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests. Therefore, annotations like
  AllowCrossThreadAccess()/crossThreadWeakPtr() is not so essential in
  catching errors.
- There is no CrossThreadWeakPtr, so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856
==========

to

==========
Allow passing WeakPtr across threads without AllowCrossThreadAccess()

This removes AllowCrossThreadAccess() for WeakPtr and
adds CrossThreadCopier for WeakPtr instead.

This CL doesn't introduce crossThreadWeakPtr(), because:
- If the thread restriction of WeakPtr is violated, the assertions in WeakPtr
  will fail quite reliably if covered by tests. Therefore, annotations like
  AllowCrossThreadAccess()/crossThreadWeakPtr() is not so essential in
  catching errors.
- There is no CrossThreadWeakPtr, so the wrapper crossThreadWeakPtr() can be
  confusing.

BUG=597856

Committed: https://crrev.com/e656f4c55f88ea32473335e17d6fc2065f119ef2
Cr-Commit-Position: refs/heads/master@{#394154}
==========

[commit-bot: I haz the power, 2016-05-17 17:29:00]

Patchset 4 (id:??) landed as
https://crrev.com/e656f4c55f88ea32473335e17d6fc2065f119ef2
Cr-Commit-Position: refs/heads/master@{#394154}