Change the pixel tests reference image revision mechanism.
Change the pixel tests reference image revision mechanism.

Originally we put the revision in the file name.  However, this blocks the flakiness dashboard to obtain the images.  So now we keep a seperate revision file in the format of testname_revision.ref, whereas the ref image is always testname.png no matter what's the revision.

BUG=
TEST=GPU bots, pixel tests
R=jbates
Review URL: https://chromiumcodereview.appspot.com/9692052

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@126457 0039d316-1c4b-4281-b951-d872f2087c98

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