unity-panel-service leaks memory

[Karl-Philipp Richter]

After about 24 hours, `/usr/lib/x86_64-linux-gnu/unity/unity-panel-service` consumes about 10 GB of RAM which always makes the PC unresponsive due to swapping if I forget to turn it off or kill `unity-panel-service`.

On console I see `(unity-panel-service:4934): LIBDBUSMENU-GLIB-WARNING **: Sync failed, now we've got extra layout nodes.` about every 5 seconds.

Not a duplicate/revival of https://bugs.launchpad.net/ubuntu/+source/unity/+bug/830287 since the testcase doesn't trigger increase of memory. Might be a duplicate of https://bugs.launchpad.net/ubuntu/+source/unity/+bug/722972.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: unity-services 7.5.0+16.10.20160906.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-28.30-generic 4.8.6
Uname: Linux 4.8.0-28-generic x86_64
NonfreeKernelModules: openafs zfs zunicode zcommon znvpair zavl
.tmp.unity_support_test.0:

ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CompizPlugins: »/apps/compiz-1/general/screen0/options/active_plugins« wurde kein Wert zugewiesen
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Fri Dec 2 18:57:48 2016
DistUpgraded: 2016-10-17 13:28:03,057 ERROR got error from PostInstallScript ./xorg_fix_proprietary.py (g-exec-error-quark: Kindprozess »./xorg_fix_proprietary.py« konnte nicht ausgeführt werden (No such file or directory) (8))
DistroCodename: yakkety
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo 3rd Gen Core processor Graphics Controller [17aa:3904]
InstallationDate: Installed on 2015-12-12 (356 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: LENOVO 20221
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.8.0-28-generic root=UUID=791b47e7-915d-4d5a-bce0-d7e9b660a2ab ro rootflags=subvol=ubuntu-main-root
SourcePackage: unity
UpgradeStatus: Upgraded to yakkety on 2016-10-17 (46 days ago)
dmi.bios.date: 07/12/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 71CN51WW(V1.21)
dmi.board.asset.tag: No Asset Tag
dmi.board.name: INVALID
dmi.board.vendor: LENOVO
dmi.board.version: 31900003WIN8 STD MLT
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad Z500 Touch
dmi.modalias: dmi:bvnLENOVO:bvr71CN51WW(V1.21):bd07/12/2013:svnLENOVO:pn20221:pvrLenovoIdeaPadZ500Touch:rvnLENOVO:rnINVALID:rvr31900003WIN8STDMLT:cvnLENOVO:ct10:cvrLenovoIdeaPadZ500Touch:
dmi.product.name: 20221
dmi.product.version: Lenovo IdeaPad Z500 Touch
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.13.0+16.10.20160818.2-0ubuntu2
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.73+git20161127.23d10b82-0ubuntu0ricotz~yakkety
version.libgl1-mesa-dri: libgl1-mesa-dri 13.0.1+git20161127+13.0.f7b58a37-0ubuntu0ricotz~yakkety
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 13.0.1+git20161127+13.0.f7b58a37-0ubuntu0ricotz~yakkety
version.xserver-xorg-core: xserver-xorg-core 2:1.18.4-1ubuntu6.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.8.99+git20161127.487aa62a-0ubuntu0ricotz~yakkety
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20161127.bde94605-0ubuntu0ricotz~yakkety
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.13+git20161127.1516d35b-0ubuntu0ricotz~yakkety
xserver.bootTime: Thu Dec 1 21:11:14 2016
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.4-1ubuntu6.1
xserver.video_driver: modeset