Fix UMA reporting for EME
Fix UMA reporting for EME

UMA_* macros assume a constant name *across the process' lifetime*,
not just in a single object.

TEST=Load pages using different key-systems in the same renderer; no crash & histograms are correct.


Review URL: https://chromiumcodereview.appspot.com/11272041

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@164317 0039d316-1c4b-4281-b951-d872f2087c98

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