fixup! ozone integration

fixup! ozone integration

Since http://165.213.202.130/gerrit/#/c/80317/ we
hit the follow ASSERT upon launch (desktop debug build
of content shell).

[0529/143728:FATAL:at_exit.cc(53)] Check failed: false. Tried to RegisterCallback without an AtExitManager
 #0 0x000000792167 base::debug::StackTrace::StackTrace()
 #1 0x0000006cca71 logging::LogMessage::~LogMessage()
 #2 0x0000006b07e5 base::AtExitManager::RegisterTask()
 #3 0x000004ad9078 ui::DeviceDataManager::DeviceDataManager()
 #4 0x000004ad92b9 ui::DeviceDataManager::CreateInstance()
 #5 0x0000013b78a3 ui::OzonePlatform::InitializeForUI()
 #6 0x000000505f70 efl::Initialize()
 #7 0x00000041fb1e main
 #8 0x7ffff302aec5 __libc_start_main
 #9 0x00000041fa34 <unknown>

AtExitManager has to be init'ed before frame #6.

Similarly to [1] and [2], add a AtExitManager variable
declared as a local variable in 'main'.

[1] https://code.google.com/p/chromium/codesearch#chromium/src/ui/ozone/demo/ozone_demo.cc&ct=rc&cd=51&q=atexitmanager&sq=package:chromium&l=314&dr=C
[2] https://code.google.com/p/chromium/codesearch#chromium/src/mandoline/app/desktop/main.cc&q=atexitmanager&sq=package:chromium&l=13&dr=C

Bug: http://107.108.218.239/bugzilla/show_bug.cgi?id=8054
Reviewed by: Balazs Kelemen, arno renevier

Change-Id: I8045ce570d6839da068c5e5aa2b704b1c736af54
Signed-off-by: Antonio Gomes <a1.gomes@samsung.com>