Fix use-after-free when browser is closed during a drop-drop on desktop Linux

Fix use-after-free when browser is closed during a drop-drop on desktop Linux

This CL is a follow-on to https://codereview.chromium.org/795303002/ which fixed
this bug on Windows and ChromeOS

BUG=438365
TEST=BookmarkBarViewTest22.CloseSourceBrowserDuringDrag
R=sadrul
TBR=sky (For enabling BookmarkBarViewTest22.* on Desktop Linux)

Committed: https://crrev.com/d581087f4c8ff00a67f8a088692ab7442430608d
Cr-Commit-Position: refs/heads/master@{#309830}

[pkotwicz, 2014-12-20 19:01:10]

Patchset #2 (id:20001) has been deleted

[pkotwicz, 2014-12-20 19:02:14]

Patchset #2 (id:40001) has been deleted

[pkotwicz, 2014-12-20 19:27:18]

pkotwicz@chromium.org changed reviewers:
+ sadrul@chromium.org

[pkotwicz, 2014-12-20 19:27:40]

Sadrul, PTAL

[sadrul, 2014-12-22 16:34:31]

https://codereview.chromium.org/796253002/diff/60001/ui/views/widget/desktop_...
File ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.cc (right):

https://codereview.chromium.org/796253002/diff/60001/ui/views/widget/desktop_...
ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.cc:436:
move_loop_->EndMoveLoop();
Should |move_loop_| dtor make sure it EndMoveLoop()s when appropriate? Does that
need this DDDClientAuraX11 to be alive?

[pkotwicz, 2014-12-22 18:26:36]

https://codereview.chromium.org/796253002/diff/60001/ui/views/widget/desktop_...
File ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.cc (right):

https://codereview.chromium.org/796253002/diff/60001/ui/views/widget/desktop_...
ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.cc:436:
move_loop_->EndMoveLoop();
|move_loop_| calls back to DDDClientAuraX11::OnMoveLoopEnded(). So yes,
DDDClientAuraX11 needs to be alive when EndMoveLoop() is called.

The reason that I changed the ordering of
"g_live_client_map.Get().erase(xwindow_);" is so that SendXdndLeave() short
circuits and does not send an actual X event. (Sending the X event was causing
an X error. In production, we ignore X errors, but not in tests)

[sadrul, 2014-12-22 18:30:23]

OK. LGTM

[pkotwicz, 2015-01-01 19:52:32]

The CQ bit was checked by pkotwicz@chromium.org

[commit-bot: I haz the power, 2015-01-01 19:53:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/796253002/80001

[commit-bot: I haz the power, 2015-01-01 19:59:07]

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

[commit-bot: I haz the power, 2015-01-01 19:59:08]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[pkotwicz, 2015-01-01 21:50:33]

The CQ bit was checked by pkotwicz@chromium.org

[commit-bot: I haz the power, 2015-01-01 21:51:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/796253002/80001

[commit-bot: I haz the power, 2015-01-01 21:54:35]

Committed patchset #3 (id:80001)

[commit-bot: I haz the power, 2015-01-01 21:55:17]

Patchset 3 (id:??) landed as
https://crrev.com/d581087f4c8ff00a67f8a088692ab7442430608d
Cr-Commit-Position: refs/heads/master@{#309830}