The base unittests were succeeding for the isolated tests, but failed when all tests were run because some tests run without a message loop.  The  observer_list_threadsafe allowed AddObserver to run with null message loops.  But, if you call Notify after doing so, then the notify call would attempt to use the registered "null" ptr to a message loop.
The base unittests were succeeding for the isolated
tests, but failed when all tests were run because
some tests run without a message loop.  The 
observer_list_threadsafe allowed AddObserver to run
with null message loops.  But, if you call Notify
after doing so, then the notify call would attempt
to use the registered "null" ptr to a message loop.

This crashed, of course.

Review URL: http://codereview.chromium.org/9045

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@4459 0039d316-1c4b-4281-b951-d872f2087c98

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