Show an error update engine status for all unknown states.
Show an error update engine status for all unknown states.

The primary reason for this patch is so that I can add a new UPDATE_STATUS
enum value to libcros without breaking the Chrome OS build with the following
error:

"Right now we get the following error with LKGR of Chrome:
update_observer.cc: In member function 'virtual void
chromeos::UpdateObserver::Changed(chromeos::UpdateLibrary*)':
update_observer.cc:26: error: enumeration value
'UPDATE_STATUS_REPORTING_ERROR_EVENT' not handled in switch"

BUG=560
TEST=emerged chromeos-chrome with modified libcros, unit tests

Review URL: http://codereview.chromium.org/3053010

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@53409 0039d316-1c4b-4281-b951-d872f2087c98

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