In some cases (related to window.open() with no contents, see bug for more details) we may get notified of SSL error or mixed-contents without a NavigationEntry. This CL ensures we don't crash in that case.
In some cases (related to window.open() with no contents, see bug for more details) we may get notified of SSL error or mixed-contents without a NavigationEntry.
This CL ensures we don't crash in that case.

BUG=3845
TEST=See bug.
Review URL: http://codereview.chromium.org/17218

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@7644 0039d316-1c4b-4281-b951-d872f2087c98

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