Eliminate boiler plate callback code from gdata_file_system.cc
Eliminate boiler plate callback code from gdata_file_system.cc

Replace 'relay' callbacks with CreateRelayCallback

BUG=126850
TEST=unit_tests --gtest_filter="GData*"


Review URL: https://chromiumcodereview.appspot.com/10387173

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@139526 0039d316-1c4b-4281-b951-d872f2087c98

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