Revert of Remove MessageLoop destruction observer from mojo::Watcher.

Revert of Remove MessageLoop destruction observer from mojo::Watcher. (patchset #2 id:20001 of https://codereview.chromium.org/2475273003/ )

Reason for revert:
I'm suspecting that this CL is causing these two
layout tests to crash on WebKit Linux Precise Leak bot:
broadcastchannel/blobs.html
broadcastchannel/workers.html

because they are crashing on mojo::SyncHandleRegistry in a check for watcher pointer.

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Precise%20Leak/builds/1578

And this CL is the only CL in the build that touches on mojo watcher.

Original issue's description:
> Remove MessageLoop destruction observer from mojo::Watcher.
>
> mojo::Watcher currently registers itself as a destruction observer
> of the MessageLoop on which it is instantiated. When it is notified
> that the MessageLoop is being destroyed, it invokes its callback
> with MOJO_RESULT_ABORTED.
>
> This CL removes the MessageLoop destruction observer from
> mojo::Watcher. This allows mojo::Watcher to be instantiated on a
> thread that doesn't run a MessageLoop (e.g. TaskScheduler threads).
> No existing code depends on the MOJO_RESULT_ABORTED notification.
>
> BUG=604762
>
> Committed: https://crrev.com/da6bd89a95fc8c444720f3d76ac67b91dfd70280
> Cr-Commit-Position: refs/heads/master@{#430637}

TBR=rockot@chromium.org,yzshen@chromium.org,fdoray@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=604762
Committed: https://crrev.com/ee88cfeecda2a6fbc58ac7d2635e048ed39f28cf
Cr-Commit-Position: refs/heads/master@{#430675}

[xlai (Olivia), 2016-11-08 19:04:02]

The CQ bit was checked by xlai@chromium.org

[xlai (Olivia), 2016-11-08 19:04:02]

Created Revert of Remove MessageLoop destruction observer from mojo::Watcher.

[commit-bot: I haz the power, 2016-11-08 19:04:37]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-08 19:05:41]

Description was changed from

==========
Revert of Remove MessageLoop destruction observer from mojo::Watcher. (patchset
#2 id:20001 of https://codereview.chromium.org/2475273003/ )

Reason for revert:
I'm suspecting that this CL is causing these two
layout tests to crash on WebKit Linux Precise Leak bot:
broadcastchannel/blobs.html
broadcastchannel/workers.html

because they are crashing on mojo::SyncHandleRegistry in a check for watcher
pointer.

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Precis...

And this CL is the only CL in the build that touches on mojo watcher. 



Original issue's description:
> Remove MessageLoop destruction observer from mojo::Watcher.
> 
> mojo::Watcher currently registers itself as a destruction observer
> of the MessageLoop on which it is instantiated. When it is notified
> that the MessageLoop is being destroyed, it invokes its callback
> with MOJO_RESULT_ABORTED.
> 
> This CL removes the MessageLoop destruction observer from
> mojo::Watcher. This allows mojo::Watcher to be instantiated on a
> thread that doesn't run a MessageLoop (e.g. TaskScheduler threads).
> No existing code depends on the MOJO_RESULT_ABORTED notification.
> 
> BUG=604762
> 
> Committed: https://crrev.com/da6bd89a95fc8c444720f3d76ac67b91dfd70280
> Cr-Commit-Position: refs/heads/master@{#430637}

TBR=rockot@chromium.org,yzshen@chromium.org,fdoray@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=604762
==========

to

==========
Revert of Remove MessageLoop destruction observer from mojo::Watcher. (patchset
#2 id:20001 of https://codereview.chromium.org/2475273003/ )

Reason for revert:
I'm suspecting that this CL is causing these two
layout tests to crash on WebKit Linux Precise Leak bot:
broadcastchannel/blobs.html
broadcastchannel/workers.html

because they are crashing on mojo::SyncHandleRegistry in a check for watcher
pointer.

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Precis...

And this CL is the only CL in the build that touches on mojo watcher. 



Original issue's description:
> Remove MessageLoop destruction observer from mojo::Watcher.
> 
> mojo::Watcher currently registers itself as a destruction observer
> of the MessageLoop on which it is instantiated. When it is notified
> that the MessageLoop is being destroyed, it invokes its callback
> with MOJO_RESULT_ABORTED.
> 
> This CL removes the MessageLoop destruction observer from
> mojo::Watcher. This allows mojo::Watcher to be instantiated on a
> thread that doesn't run a MessageLoop (e.g. TaskScheduler threads).
> No existing code depends on the MOJO_RESULT_ABORTED notification.
> 
> BUG=604762
> 
> Committed: https://crrev.com/da6bd89a95fc8c444720f3d76ac67b91dfd70280
> Cr-Commit-Position: refs/heads/master@{#430637}

TBR=rockot@chromium.org,yzshen@chromium.org,fdoray@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=604762
==========

[commit-bot: I haz the power, 2016-11-08 19:05:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-08 19:39:31]

Description was changed from

==========
Revert of Remove MessageLoop destruction observer from mojo::Watcher. (patchset
#2 id:20001 of https://codereview.chromium.org/2475273003/ )

Reason for revert:
I'm suspecting that this CL is causing these two
layout tests to crash on WebKit Linux Precise Leak bot:
broadcastchannel/blobs.html
broadcastchannel/workers.html

because they are crashing on mojo::SyncHandleRegistry in a check for watcher
pointer.

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Precis...

And this CL is the only CL in the build that touches on mojo watcher. 



Original issue's description:
> Remove MessageLoop destruction observer from mojo::Watcher.
> 
> mojo::Watcher currently registers itself as a destruction observer
> of the MessageLoop on which it is instantiated. When it is notified
> that the MessageLoop is being destroyed, it invokes its callback
> with MOJO_RESULT_ABORTED.
> 
> This CL removes the MessageLoop destruction observer from
> mojo::Watcher. This allows mojo::Watcher to be instantiated on a
> thread that doesn't run a MessageLoop (e.g. TaskScheduler threads).
> No existing code depends on the MOJO_RESULT_ABORTED notification.
> 
> BUG=604762
> 
> Committed: https://crrev.com/da6bd89a95fc8c444720f3d76ac67b91dfd70280
> Cr-Commit-Position: refs/heads/master@{#430637}

TBR=rockot@chromium.org,yzshen@chromium.org,fdoray@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=604762
==========

to

==========
Revert of Remove MessageLoop destruction observer from mojo::Watcher. (patchset
#2 id:20001 of https://codereview.chromium.org/2475273003/ )

Reason for revert:
I'm suspecting that this CL is causing these two
layout tests to crash on WebKit Linux Precise Leak bot:
broadcastchannel/blobs.html
broadcastchannel/workers.html

because they are crashing on mojo::SyncHandleRegistry in a check for watcher
pointer.

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Precis...

And this CL is the only CL in the build that touches on mojo watcher.

Original issue's description:
> Remove MessageLoop destruction observer from mojo::Watcher.
>
> mojo::Watcher currently registers itself as a destruction observer
> of the MessageLoop on which it is instantiated. When it is notified
> that the MessageLoop is being destroyed, it invokes its callback
> with MOJO_RESULT_ABORTED.
>
> This CL removes the MessageLoop destruction observer from
> mojo::Watcher. This allows mojo::Watcher to be instantiated on a
> thread that doesn't run a MessageLoop (e.g. TaskScheduler threads).
> No existing code depends on the MOJO_RESULT_ABORTED notification.
>
> BUG=604762
>
> Committed: https://crrev.com/da6bd89a95fc8c444720f3d76ac67b91dfd70280
> Cr-Commit-Position: refs/heads/master@{#430637}

TBR=rockot@chromium.org,yzshen@chromium.org,fdoray@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=604762

Committed: https://crrev.com/ee88cfeecda2a6fbc58ac7d2635e048ed39f28cf
Cr-Commit-Position: refs/heads/master@{#430675}
==========

[commit-bot: I haz the power, 2016-11-08 19:39:32]

Patchset 1 (id:??) landed as
https://crrev.com/ee88cfeecda2a6fbc58ac7d2635e048ed39f28cf
Cr-Commit-Position: refs/heads/master@{#430675}