Check for NULL pointer before using.
Check for NULL pointer before using.

Instant extended API mode doesn't instantiate the keyword provider, so
it may be NULL. Check for that before using.

BUG=156872
R=pkasting@chromium.org
TEST=Steps to reproduce in bug shouldn't cause a crash anymore.


Review URL: https://chromiumcodereview.appspot.com/11189098

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@163081 0039d316-1c4b-4281-b951-d872f2087c98

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