Fix a crash in the code which attempts to append the user agent to the list of outgoing headers in ChromeFrame sub requests. The crash occurs because the current headers passed in the BeginningTransaction are NULL.
Fix a crash in the code which attempts to append the user agent to the list of outgoing
headers in ChromeFrame sub requests. The crash occurs because the current headers passed
in the BeginningTransaction are NULL.

Fixes bug http://code.google.com/p/chromium/issues/detail?id=62853

Bug=62853

Review URL: http://codereview.chromium.org/4792002

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@65834 0039d316-1c4b-4281-b951-d872f2087c98

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