Oilpan: have PromiseTracker callback keep a WeakPersistent<>.

Oilpan: have PromiseTracker callback keep a WeakPersistent<>.

For the v8 callback objects that PromiseTrackers create, insist on using
a WeakPersistent<> back reference to the PromiseTracker when Oilpan
is enabled.

R=haraken
BUG=340522
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200963

[sof, 2015-08-20 21:20:28]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2015-08-20 21:20:28]

please take a look.

[haraken, 2015-08-21 00:16:25]

haraken@chromium.org changed reviewers:
+ haraken@chromium.org

[haraken, 2015-08-21 00:16:25]

LGTM

https://codereview.chromium.org/1301253002/diff/1/Source/core/inspector/Promi...
File Source/core/inspector/PromiseTracker.cpp (right):

https://codereview.chromium.org/1301253002/diff/1/Source/core/inspector/Promi...
Source/core/inspector/PromiseTracker.cpp:40:
m_tracker->m_listener->didUpdatePromise(InspectorFrontend::Debugger::EventType::Gc,
promiseDetails.release());

This does complicated things like posting a message, posting a task etc in a
destructor of PromiseWeakCallbackData. This is no problem since the
PromiseWeakCallbackData is off the heap but a bit nasty.

[sof, 2015-08-21 05:16:59]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-08-21 05:17:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1301253002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1301253002/1

[commit-bot: I haz the power, 2015-08-21 05:21:23]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200963