Set |contents_mime_type| early enough so that the encoding menu is enabled on the first load of a page in a tab. 
Set |contents_mime_type| early enough so that the encoding menu is enabled on the first load of a page
in a tab. 


BUG=2929
TEST=Launch Chrome, go to www.google.com and make sure that the encoding menu is enabled.

Review URL: http://codereview.chromium.org/7894

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@3844 0039d316-1c4b-4281-b951-d872f2087c98

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