Fix potential crash in Browser::OpenURLAtIndex.
Fix potential crash in Browser::OpenURLAtIndex.

This is a bit of a Coverity nit, but if disposition
SUPPRESS_OPEN is ever passed in to this function,
it will crash because we try to call Focus on a
new_contents pointer that is null. I verified this
by hard coding the disposition as we open URLs.

BUG=17101
TEST=No significant change.

Review URL: http://codereview.chromium.org/155773

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@23532 0039d316-1c4b-4281-b951-d872f2087c98

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