gdata: Fix an unnecessary DCHECK for debug builds.
gdata: Fix an unnecessary DCHECK for debug builds.

In GDataFileSystem::OnGetFileInfoCompleteForGetFileByPath it is possible
for |error| to be not OK and the |file_info| to be NULL. This is handled
in the GetResolvedFileByPath() where |get_file_callback| to be invoked
with PLATFORM_FILE_ERROR_NOT_FOUND.

To prevent unnecessarily terminate the process during debugging, the DCHECK
should only trigger when |error| is OK yet |file_info| is NULL.

BUG=
TEST=local

Review URL: https://chromiumcodereview.appspot.com/10561033

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@142805 0039d316-1c4b-4281-b951-d872f2087c98

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