Revert 196011 "Remove Shadow DOM runtime flag."
Revert 196011 "Remove Shadow DOM runtime flag."

This seems to have broken a lot of random browser tests.

> Remove Shadow DOM runtime flag.
> 
> This is the chromium side patch.
> The blink side patch will follow.
> 
> BUG=230744.
> 
> Review URL: https://codereview.chromium.org/14167011

TBR=hayato@chromium.org

Review URL: https://codereview.chromium.org/13966017

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@196015 0039d316-1c4b-4281-b951-d872f2087c98

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