Update popup blocker behavior and tests

Update popup blocker behavior and tests

The tests now also check whether a background or foreground tab is
opened. We also make the behavior of the popup blocker match the
behavior of the render view (which is to not mess with the disposition)

BUG=431335
R=mkwst@chromium.org

Committed: https://crrev.com/7c3b40a06e92cd393f6e36812399c8976ca93486
Cr-Commit-Position: refs/heads/master@{#304593}

[Mike West, 2014-11-17 10:01:28]

LGTM.

[jochen (gone - plz use gerrit), 2014-11-17 16:15:17]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-11-17 16:15:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/731083002/20001

[commit-bot: I haz the power, 2014-11-17 17:18:36]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-11-17 17:18:37]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[jochen (gone - plz use gerrit), 2014-11-17 20:42:21]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-11-17 20:43:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/731083002/40001

[commit-bot: I haz the power, 2014-11-17 22:08:58]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-11-17 22:08:59]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[jochen (gone - plz use gerrit), 2014-11-18 11:52:18]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-11-18 11:53:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/731083002/60001

[jochen (gone - plz use gerrit), 2014-11-18 12:29:25]

The CQ bit was unchecked by jochen@chromium.org

[jochen (gone - plz use gerrit), 2014-11-18 12:51:34]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-11-18 12:52:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/731083002/80001

[commit-bot: I haz the power, 2014-11-18 13:33:33]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2014-11-18 13:34:20]

Patchset 5 (id:??) landed as
https://crrev.com/7c3b40a06e92cd393f6e36812399c8976ca93486
Cr-Commit-Position: refs/heads/master@{#304593}