[cros, Aura] Fix login screen crash on boot.
[cros, Aura] Fix login screen crash on boot.

Crash was caused by the uninitialized ScreenAura instance used in
chromeos::CalculateScreenBounds chrome/browser/chromeos/login/helper.cc:164
Moved initialization of login screen classes right before message loop start so that Desktop/Screen instances are initialized.

Also fixed crash during sign in.

TBR=nkostylev@chromium.org
BUG=103892
TEST=Boot with Aura build, sign in. No crashes

Original CL: http://codereview.chromium.org/8511059/

landing for nkostylev@chromium.org,

Review URL: http://codereview.chromium.org/8540014

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@109666 0039d316-1c4b-4281-b951-d872f2087c98

krieger-od/nwjs_chromium.src,ltilve/chromium,Jonekee/chromium.src,crosswalk-project/chromium-crosswalk-efl,chuan9/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,anirudhSK/chromium,Pluto-tv/chromium-crosswalk,littlstar/chromium.src,junmin-zhu/chromium-rivertrail,nacl-webkit/chrome_deps,junmin-zhu/chromium-rivertrail,hujiajie/pa-chromium,pozdnyakov/chromium-crosswalk,Chilledheart/chromium,keishi/chromium,dednal/chromium.src,ChromiumWebApps/chromium,robclark/chromium,dednal/chromium.src,nacl-webkit/chrome_deps,ChromiumWebApps/chromium,rogerwang/chromium,bright-sparks/chromium-spacewalk,chuan9/chromium-crosswalk,ltilve/chromium,jaruba/chromium.src,hgl888/chromium-crosswalk,M4sse/chromium.src,Chilledheart/chromium,rogerwang/chromium,ondra-novak/chromium.src,Pluto-tv/chromium-crosswalk,Fireblend/chromium-crosswalk,hujiajie/pa-chromium,PeterWangIntel/chromium-crosswalk,markYoungH/chromium.src,jaruba/chromium.src,littlstar/chromium.src,Fireblend/chromium-crosswalk,mogoweb/chromium-crosswalk,hgl888/chromium-crosswalk,hgl888/chromium-crosswalk-efl,keishi/chromium,TheTypoMaster/chromium-crosswalk,patrickm/chromium.src,dushu1203/chromium.src,junmin-zhu/chromium-rivertrail,TheTypoMaster/chromium-crosswalk,bright-sparks/chromium-spacewalk,dednal/chromium.src,patrickm/chromium.src,axinging/chromium-crosswalk,markYoungH/chromium.src,krieger-od/nwjs_chromium.src,chuan9/chromium-crosswalk,ondra-novak/chromium.src,axinging/chromium-crosswalk,Jonekee/chromium.src,robclark/chromium,nacl-webkit/chrome_deps,nacl-webkit/chrome_deps,Pluto-tv/chromium-crosswalk,patrickm/chromium.src,M4sse/chromium.src,jaruba/chromium.src,markYoungH/chromium.src,crosswalk-project/chromium-crosswalk-efl,timopulkkinen/BubbleFish,mogoweb/chromium-crosswalk,mogoweb/chromium-crosswalk,ChromiumWebApps/chromium,dednal/chromium.src,hujiajie/pa-chromium,robclark/chromium,anirudhSK/chromium,axinging/chromium-crosswalk,keishi/chromium,dushu1203/chromium.src,mohamed--abdel-maksoud/chromium.src,junmin-zhu/chromium-rivertrail,dednal/chromium.src,PeterWangIntel/chromium-crosswalk,patrickm/chromium.src,Just-D/chromium-1,anirudhSK/chromium,robclark/chromium,TheTypoMaster/chromium-crosswalk,ltilve/chromium,zcbenz/cefode-chromium,markYoungH/chromium.src,Jonekee/chromium.src,dushu1203/chromium.src,nacl-webkit/chrome_deps,ChromiumWebApps/chromium,hujiajie/pa-chromium,Chilledheart/chromium,Fireblend/chromium-crosswalk,dushu1203/chromium.src,patrickm/chromium.src,markYoungH/chromium.src,dushu1203/chromium.src,fujunwei/chromium-crosswalk,Jonekee/chromium.src,patrickm/chromium.src,Chilledheart/chromium,crosswalk-project/chromium-crosswalk-efl,Just-D/chromium-1,zcbenz/cefode-chromium,timopulkkinen/BubbleFish,pozdnyakov/chromium-crosswalk,keishi/chromium,chuan9/chromium-crosswalk,Jonekee/chromium.src,fujunwei/chromium-crosswalk,robclark/chromium,Jonekee/chromium.src,pozdnyakov/chromium-crosswalk,littlstar/chromium.src,dednal/chromium.src,fujunwei/chromium-crosswalk,hgl888/chromium-crosswalk-efl,zcbenz/cefode-chromium,robclark/chromium,M4sse/chromium.src,markYoungH/chromium.src,zcbenz/cefode-chromium,dednal/chromium.src,axinging/chromium-crosswalk,jaruba/chromium.src,anirudhSK/chromium,keishi/chromium,hgl888/chromium-crosswalk,rogerwang/chromium,bright-sparks/chromium-spacewalk,M4sse/chromium.src,mogoweb/chromium-crosswalk,keishi/chromium,hgl888/chromium-crosswalk,robclark/chromium,pozdnyakov/chromium-crosswalk,hgl888/chromium-crosswalk,anirudhSK/chromium,robclark/chromium,fujunwei/chromium-crosswalk,keishi/chromium,krieger-od/nwjs_chromium.src,ltilve/chromium,dednal/chromium.src,markYoungH/chromium.src,axinging/chromium-crosswalk,M4sse/chromium.src,rogerwang/chromium,ltilve/chromium,anirudhSK/chromium,junmin-zhu/chromium-rivertrail,hgl888/chromium-crosswalk-efl,crosswalk-project/chromium-crosswalk-efl,ChromiumWebApps/chromium,markYoungH/chromium.src,PeterWangIntel/chromium-crosswalk,rogerwang/chromium,anirudhSK/chromium,mohamed--abdel-maksoud/chromium.src,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,hgl888/chromium-crosswalk-efl,nacl-webkit/chrome_deps,bright-sparks/chromium-spacewalk,M4sse/chromium.src,timopulkkinen/BubbleFish,patrickm/chromium.src,hgl888/chromium-crosswalk-efl,krieger-od/nwjs_chromium.src,Chilledheart/chromium,dushu1203/chromium.src,junmin-zhu/chromium-rivertrail,M4sse/chromium.src,dushu1203/chromium.src,TheTypoMaster/chromium-crosswalk,anirudhSK/chromium,krieger-od/nwjs_chromium.src,Fireblend/chromium-crosswalk,axinging/chromium-crosswalk,hujiajie/pa-chromium,Pluto-tv/chromium-crosswalk,ChromiumWebApps/chromium,jaruba/chromium.src,pozdnyakov/chromium-crosswalk,hgl888/chromium-crosswalk-efl,ChromiumWebApps/chromium,chuan9/chromium-crosswalk,nacl-webkit/chrome_deps,rogerwang/chromium,hgl888/chromium-crosswalk-efl,ltilve/chromium,Pluto-tv/chromium-crosswalk,anirudhSK/chromium,timopulkkinen/BubbleFish,hujiajie/pa-chromium,Just-D/chromium-1,hgl888/chromium-crosswalk,hujiajie/pa-chromium,ChromiumWebApps/chromium,Pluto-tv/chromium-crosswalk,rogerwang/chromium,junmin-zhu/chromium-rivertrail,pozdnyakov/chromium-crosswalk,pozdnyakov/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,rogerwang/chromium,krieger-od/nwjs_chromium.src,mogoweb/chromium-crosswalk,jaruba/chromium.src,zcbenz/cefode-chromium,bright-sparks/chromium-spacewalk,jaruba/chromium.src,Jonekee/chromium.src,ltilve/chromium,Jonekee/chromium.src,littlstar/chromium.src,nacl-webkit/chrome_deps,PeterWangIntel/chromium-crosswalk,zcbenz/cefode-chromium,Just-D/chromium-1,Fireblend/chromium-crosswalk,ChromiumWebApps/chromium,axinging/chromium-crosswalk,ChromiumWebApps/chromium,hgl888/chromium-crosswalk,bright-sparks/chromium-spacewalk,Just-D/chromium-1,Jonekee/chromium.src,Chilledheart/chromium,ondra-novak/chromium.src,keishi/chromium,timopulkkinen/BubbleFish,ondra-novak/chromium.src,axinging/chromium-crosswalk,ltilve/chromium,hgl888/chromium-crosswalk-efl,M4sse/chromium.src,Just-D/chromium-1,Chilledheart/chromium,Pluto-tv/chromium-crosswalk,zcbenz/cefode-chromium,fujunwei/chromium-crosswalk,Chilledheart/chromium,dushu1203/chromium.src,littlstar/chromium.src,jaruba/chromium.src,Fireblend/chromium-crosswalk,Jonekee/chromium.src,hujiajie/pa-chromium,axinging/chromium-crosswalk,ondra-novak/chromium.src,rogerwang/chromium,krieger-od/nwjs_chromium.src,Fireblend/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,Pluto-tv/chromium-crosswalk,patrickm/chromium.src,timopulkkinen/BubbleFish,nacl-webkit/chrome_deps,hgl888/chromium-crosswalk-efl,anirudhSK/chromium,keishi/chromium,mohamed--abdel-maksoud/chromium.src,littlstar/chromium.src,timopulkkinen/BubbleFish,littlstar/chromium.src,junmin-zhu/chromium-rivertrail,TheTypoMaster/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,anirudhSK/chromium,robclark/chromium,patrickm/chromium.src,pozdnyakov/chromium-crosswalk,bright-sparks/chromium-spacewalk,PeterWangIntel/chromium-crosswalk,junmin-zhu/chromium-rivertrail,jaruba/chromium.src,jaruba/chromium.src,hujiajie/pa-chromium,mohamed--abdel-maksoud/chromium.src,markYoungH/chromium.src,robclark/chromium,mohamed--abdel-maksoud/chromium.src,nacl-webkit/chrome_deps,mogoweb/chromium-crosswalk,krieger-od/nwjs_chromium.src,mohamed--abdel-maksoud/chromium.src,Just-D/chromium-1,M4sse/chromium.src,pozdnyakov/chromium-crosswalk,axinging/chromium-crosswalk,littlstar/chromium.src,fujunwei/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,ondra-novak/chromium.src,keishi/chromium,fujunwei/chromium-crosswalk,bright-sparks/chromium-spacewalk,zcbenz/cefode-chromium,Fireblend/chromium-crosswalk,markYoungH/chromium.src,dushu1203/chromium.src,timopulkkinen/BubbleFish,ondra-novak/chromium.src,Just-D/chromium-1,Jonekee/chromium.src,hujiajie/pa-chromium,mogoweb/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,hujiajie/pa-chromium,ltilve/chromium,PeterWangIntel/chromium-crosswalk,rogerwang/chromium,mogoweb/chromium-crosswalk,krieger-od/nwjs_chromium.src,ondra-novak/chromium.src,timopulkkinen/BubbleFish,krieger-od/nwjs_chromium.src,pozdnyakov/chromium-crosswalk,dushu1203/chromium.src,crosswalk-project/chromium-crosswalk-efl,Pluto-tv/chromium-crosswalk,hgl888/chromium-crosswalk-efl,Just-D/chromium-1,fujunwei/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,dushu1203/chromium.src,nacl-webkit/chrome_deps,M4sse/chromium.src,pozdnyakov/chromium-crosswalk,dednal/chromium.src,mohamed--abdel-maksoud/chromium.src,chuan9/chromium-crosswalk,hgl888/chromium-crosswalk,timopulkkinen/BubbleFish,jaruba/chromium.src,mohamed--abdel-maksoud/chromium.src,mogoweb/chromium-crosswalk,bright-sparks/chromium-spacewalk,markYoungH/chromium.src,ChromiumWebApps/chromium,junmin-zhu/chromium-rivertrail,ondra-novak/chromium.src,zcbenz/cefode-chromium,axinging/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,timopulkkinen/BubbleFish,mogoweb/chromium-crosswalk,krieger-od/nwjs_chromium.src,hgl888/chromium-crosswalk,dednal/chromium.src,crosswalk-project/chromium-crosswalk-efl,fujunwei/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,keishi/chromium,anirudhSK/chromium,zcbenz/cefode-chromium,dednal/chromium.src,Chilledheart/chromium,chuan9/chromium-crosswalk,M4sse/chromium.src,chuan9/chromium-crosswalk,zcbenz/cefode-chromium,junmin-zhu/chromium-rivertrail,ChromiumWebApps/chromium,chuan9/chromium-crosswalk