Disable promotion of RenderLayers with transitions
Disable promotion of RenderLayers with transitions

This disables the promotion of RenderLayers with transitions, previously
enabled for high-DPI by http://crrev.com/201711. Enabling this caused
an excessive number of composited layers on some pages (due to overlap),
which in turn caused a large regression in scrolling performance on Google
Docs (http://crbug.com/248132). The problem of excessive layer promotion
due to overlap needs to be fixed before this can be re-enabled.

BUG=248132,246305,178119

Review URL: https://chromiumcodereview.appspot.com/16258009

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@205442 0039d316-1c4b-4281-b951-d872f2087c98

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