Fix crash when incognito split mode extension using the WebRequest API was reloaded

Fix crash when incognito split mode extension using the WebRequest API was reloaded

This fixes a CHECK assertion that was triggered if an incognito split mode
extension with two background pages (each having an active web reqeust event
listener) was restarted. The reason for the bug was that the event listener
from the incognito background page would not be unregistered properly.

BUG=224094
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=192537

[battre, 2013-04-04 09:37:23]

Hi Matt,

please take a look at this CL.

Thanks a lot,
Dominic

[Matt Perry, 2013-04-04 19:16:23]

LGTM, thanks for the quick fix!

[commit-bot: I haz the power, 2013-04-04 21:51:25]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/battre@chromium.org/13572005/1

[commit-bot: I haz the power, 2013-04-04 22:30:54]

Retried try job too often on win_x64_rel for step(s) compile
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_x64_re...

[commit-bot: I haz the power, 2013-04-05 08:17:17]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/battre@chromium.org/13572005/1

[commit-bot: I haz the power, 2013-04-05 09:46:46]

Retried try job too often on win_rel for step(s) unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-04-05 09:49:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/battre@chromium.org/13572005/1

[commit-bot: I haz the power, 2013-04-05 09:55:56]

Change committed as 192537