All worker threads should be joined before main thread's V8 isolate is destroyed

All worker threads should be joined before main thread's V8 isolate is destroyed

Currently the following scenario can happen:

1) The main thread calls blink::shutdown().
2) The main thread calls V8Initializer::shutdown(), which destroys the V8 isolate.
3) Worker threads are still running and can trigger Oilpan's GC (<== this accesses the isolate and causes crash).
4) The main thread calls modulesInitializer().shutdown() and joins all workers.

To address the issue, this CL moves 4) to between 1) and 2).

BUG=610987
Committed: https://crrev.com/3c35abf17d76b2e4fe491a703b68b17c48725eeb
Cr-Commit-Position: refs/heads/master@{#392913}

[haraken, 2016-05-11 11:11:10]

haraken@chromium.org changed reviewers:
+ jochen@chromium.org, sigbjornf@opera.com

[haraken, 2016-05-11 11:11:11]

PTAL

[sof, 2016-05-11 11:32:50]

lgtm

It looks like https://codereview.chromium.org/1775563004 didn't hold.

[haraken, 2016-05-11 11:35:00]

The CQ bit was checked by haraken@chromium.org

[commit-bot: I haz the power, 2016-05-11 11:35:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1969673004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1969673004/1

[commit-bot: I haz the power, 2016-05-11 14:07:05]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-11 14:08:56]

Description was changed from

==========
All worker threads should be joined before main thread's V8 isolate is destroyed

Currently the following scenario can happen:

1) The main thread calls blink::shutdown().
2) The main thread calls V8Initializer::shutdown(), which destroys the V8
isolate.
3) Worker threads are still running and can trigger Oilpan's GC (<== this
accesses the isolate and causes crash).
4) The main thread calls modulesInitializer().shutdown() and joins all workers.

To address the issue, this CL moves 4) to between 1) and 2).

BUG=610987
==========

to

==========
All worker threads should be joined before main thread's V8 isolate is destroyed

Currently the following scenario can happen:

1) The main thread calls blink::shutdown().
2) The main thread calls V8Initializer::shutdown(), which destroys the V8
isolate.
3) Worker threads are still running and can trigger Oilpan's GC (<== this
accesses the isolate and causes crash).
4) The main thread calls modulesInitializer().shutdown() and joins all workers.

To address the issue, this CL moves 4) to between 1) and 2).

BUG=610987

Committed: https://crrev.com/3c35abf17d76b2e4fe491a703b68b17c48725eeb
Cr-Commit-Position: refs/heads/master@{#392913}
==========

[commit-bot: I haz the power, 2016-05-11 14:08:57]

Patchset 1 (id:??) landed as
https://crrev.com/3c35abf17d76b2e4fe491a703b68b17c48725eeb
Cr-Commit-Position: refs/heads/master@{#392913}