Mac: Ignore sheets when deciding whether to dismiss a browser action popup.

Mac: Ignore sheets when deciding whether to dismiss a browser action popup.

Since Chrome 8, invoking <input type="file"> in a browser action popup
on OSX would show, then immediately close the sheet (and the popup).

This CL fixes it by ignoring loss of key status on the bubble window
when it has an attached sheet. Loss of key status (or clicks) on windows
that are sheets themselves are also ignored, otherwise dismissing the
sheet would close the bubble as well, since it's already lost its "sheet
attached" status by that stage.

BUG=61632
Committed: https://crrev.com/780dfa3dcc6fc09b3ea4999ec6a4db640556e287
Cr-Commit-Position: refs/heads/master@{#295198}

[tapted, 2014-09-16 07:51:44]

tapted@chromium.org changed reviewers:
+ rsesek@chromium.org

[tapted, 2014-09-16 08:51:31]

Patchset #3 (id:40001) has been deleted

[tapted, 2014-09-16 08:54:51]

Hi Robert, please take a look. It's a ~3 line change with a bit of
restructuring. The test was a bit of a doozie though.

[Robert Sesek, 2014-09-16 14:27:37]

LGTM. +10 points for fixing such a low bug number :).

[tapted, 2014-09-16 21:26:18]

The CQ bit was checked by tapted@chromium.org

[commit-bot: I haz the power, 2014-09-16 21:27:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/576643002/60001

[commit-bot: I haz the power, 2014-09-16 21:41:28]

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

[commit-bot: I haz the power, 2014-09-16 21:41:29]

Try jobs failed on following builders:
  android_chromium_gn_compile_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[tapted, 2014-09-16 23:09:30]

The CQ bit was checked by tapted@chromium.org

[commit-bot: I haz the power, 2014-09-16 23:10:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/576643002/60001

[commit-bot: I haz the power, 2014-09-17 00:54:49]

Committed patchset #3 (id:60001) as 0e624b68bbb85499ccfada925236f076bac6b997

[commit-bot: I haz the power, 2014-09-17 00:55:42]

Patchset 3 (id:??) landed as
https://crrev.com/780dfa3dcc6fc09b3ea4999ec6a4db640556e287
Cr-Commit-Position: refs/heads/master@{#295198}