Check Member<T> validity for stack allocated objects.

Check Member<T> validity for stack allocated objects.

For Member<T> in a stack allocated object, make the Blink GC plugin
verify that T is a GC allocated object.

R=haraken
BUG=495398
Committed: https://crrev.com/b95bbfb9b48f40a15e0ba051a41b6250dfd33698
Cr-Commit-Position: refs/heads/master@{#333217}

[sof, 2015-06-06 08:54:00]

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

[sof, 2015-06-06 08:54:01]

please take a look.

[haraken, 2015-06-06 10:29:47]

LGTM

[sof, 2015-06-06 18:08:37]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-06-06 18:08:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1167123002/1

[commit-bot: I haz the power, 2015-06-06 18:19:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-06 18:20:25]

Patchset 1 (id:??) landed as
https://crrev.com/b95bbfb9b48f40a15e0ba051a41b6250dfd33698
Cr-Commit-Position: refs/heads/master@{#333217}