Comment 2 for bug 1425085

StacktraceTop:
 unity::glib::Source::IsRunning() const () from /tmp/apport_sandbox_TZ_cxi/usr/lib/libunity-core-6.0.so.9
 unity::XdndStartStopNotifierImp::DndTimeoutSetup (this=0x2f91150) at /build/buildd/unity-7.3.1+15.04.20150219.2/launcher/XdndStartStopNotifierImp.cpp:40
 sigc::internal::signal_emit1<void, unsigned long, sigc::nil>::emit (impl=0x2f780d0, _A_a1=@0x7ffff7f9cb50: 52428812) at /usr/include/sigc++-2.0/sigc++/signal.h:1010
 emit (this=0x2c45078, _A_a1=@0x7ffff7f9cb50: 52428812) at /usr/include/sigc++-2.0/sigc++/signal.h:2801
 unity::PluginAdapter::Notify (this=0x2c44f70, window=window@entry=0x4748af0, notify=notify@entry=CompWindowNotifyUnmap) at /build/buildd/unity-7.3.1+15.04.20150219.2/unity-shared/PluginAdapter.cpp:176