[prototype user tracking] Don't skip JSGlobalProxies

[prototype user tracking] Don't skip JSGlobalProxies

For a prototype chain foo -> global_proxy -> global_object, we used to
register a dependency from foo -> global_object. This is incorrect when
the global_proxy/global_object pairing is modified, e.g. when navigating
in iframes. With this patch, we properly register foo -> global_proxy and
global_proxy -> global_object dependencies.
Additionally, when a prototype's prototype changes from null to something
else, this new usage relation must be registered if there are other users
further down on the prototype chain that might expect a complete chain of
registrations to exist (which was the case before, and must be preserved).

BUG=chromium:571517
LOG=n
R=verwaest@chromium.org

Committed: https://crrev.com/b4583c044412c1487198dd25c81a7c664ac97f23
Cr-Commit-Position: refs/heads/master@{#33119}

[Toon Verwaest, 2016-01-05 15:51:29]

lgtm

[Jakob Kummerow, 2016-01-05 15:51:48]

The CQ bit was checked by jkummerow@chromium.org

[commit-bot: I haz the power, 2016-01-05 15:51:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1559323002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1559323002/1

[commit-bot: I haz the power, 2016-01-05 16:15:05]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-01-05 16:15:54]

Description was changed from

==========
[prototype user tracking] Don't skip JSGlobalProxies

For a prototype chain foo -> global_proxy -> global_object, we used to
register a dependency from foo -> global_object. This is incorrect when
the global_proxy/global_object pairing is modified, e.g. when navigating
in iframes. With this patch, we properly register foo -> global_proxy and
global_proxy -> global_object dependencies.
Additionally, when a prototype's prototype changes from null to something
else, this new usage relation must be registered if there are other users
further down on the prototype chain that might expect a complete chain of
registrations to exist (which was the case before, and must be preserved).

BUG=chromium:571517
LOG=n
R=verwaest@chromium.org
==========

to

==========
[prototype user tracking] Don't skip JSGlobalProxies

For a prototype chain foo -> global_proxy -> global_object, we used to
register a dependency from foo -> global_object. This is incorrect when
the global_proxy/global_object pairing is modified, e.g. when navigating
in iframes. With this patch, we properly register foo -> global_proxy and
global_proxy -> global_object dependencies.
Additionally, when a prototype's prototype changes from null to something
else, this new usage relation must be registered if there are other users
further down on the prototype chain that might expect a complete chain of
registrations to exist (which was the case before, and must be preserved).

BUG=chromium:571517
LOG=n
R=verwaest@chromium.org

Committed: https://crrev.com/b4583c044412c1487198dd25c81a7c664ac97f23
Cr-Commit-Position: refs/heads/master@{#33119}
==========

[commit-bot: I haz the power, 2016-01-05 16:15:56]

Patchset 1 (id:??) landed as
https://crrev.com/b4583c044412c1487198dd25c81a7c664ac97f23
Cr-Commit-Position: refs/heads/master@{#33119}