Set the font size in about:version explicitly.
Set the font size in about:version explicitly.

about_version.css relies on the font-size in <body> being 100%, which
became not the case any more after we included text_defaults.css. To restore
the previous font-size, we set the font-size in body to 100%.

BUG=443765
TEST=Go to about:version, the computed size for user agent string is  13px
while the computed size for labels is ~ 14px.The text in the upper-right corner (in LTR locale) should be about 11px.

Review URL: https://codereview.chromium.org/814143003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#309273}

Pluto-tv/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,axinging/chromium-crosswalk,Chilledheart/chromium,M4sse/chromium.src,markYoungH/chromium.src,Pluto-tv/chromium-crosswalk,axinging/chromium-crosswalk,hgl888/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,markYoungH/chromium.src,M4sse/chromium.src,dushu1203/chromium.src,mohamed--abdel-maksoud/chromium.src,axinging/chromium-crosswalk,Just-D/chromium-1,Jonekee/chromium.src,jaruba/chromium.src,mohamed--abdel-maksoud/chromium.src,ltilve/chromium,dednal/chromium.src,PeterWangIntel/chromium-crosswalk,fujunwei/chromium-crosswalk,Pluto-tv/chromium-crosswalk,hgl888/chromium-crosswalk,dushu1203/chromium.src,axinging/chromium-crosswalk,jaruba/chromium.src,markYoungH/chromium.src,fujunwei/chromium-crosswalk,fujunwei/chromium-crosswalk,dushu1203/chromium.src,Just-D/chromium-1,axinging/chromium-crosswalk,dushu1203/chromium.src,mohamed--abdel-maksoud/chromium.src,ltilve/chromium,Just-D/chromium-1,Pluto-tv/chromium-crosswalk,hgl888/chromium-crosswalk,chuan9/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,Pluto-tv/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,ltilve/chromium,Jonekee/chromium.src,hgl888/chromium-crosswalk,M4sse/chromium.src,Just-D/chromium-1,dednal/chromium.src,dednal/chromium.src,markYoungH/chromium.src,chuan9/chromium-crosswalk,fujunwei/chromium-crosswalk,markYoungH/chromium.src,Jonekee/chromium.src,Fireblend/chromium-crosswalk,ltilve/chromium,PeterWangIntel/chromium-crosswalk,Jonekee/chromium.src,dushu1203/chromium.src,dednal/chromium.src,markYoungH/chromium.src,Chilledheart/chromium,Just-D/chromium-1,chuan9/chromium-crosswalk,Fireblend/chromium-crosswalk,dushu1203/chromium.src,axinging/chromium-crosswalk,jaruba/chromium.src,M4sse/chromium.src,TheTypoMaster/chromium-crosswalk,jaruba/chromium.src,PeterWangIntel/chromium-crosswalk,Chilledheart/chromium,TheTypoMaster/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,dushu1203/chromium.src,ltilve/chromium,krieger-od/nwjs_chromium.src,ltilve/chromium,hgl888/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,krieger-od/nwjs_chromium.src,krieger-od/nwjs_chromium.src,Fireblend/chromium-crosswalk,fujunwei/chromium-crosswalk,jaruba/chromium.src,M4sse/chromium.src,krieger-od/nwjs_chromium.src,markYoungH/chromium.src,M4sse/chromium.src,Pluto-tv/chromium-crosswalk,markYoungH/chromium.src,dednal/chromium.src,fujunwei/chromium-crosswalk,Chilledheart/chromium,jaruba/chromium.src,dednal/chromium.src,mohamed--abdel-maksoud/chromium.src,Chilledheart/chromium,TheTypoMaster/chromium-crosswalk,Jonekee/chromium.src,PeterWangIntel/chromium-crosswalk,krieger-od/nwjs_chromium.src,jaruba/chromium.src,jaruba/chromium.src,fujunwei/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,Jonekee/chromium.src,chuan9/chromium-crosswalk,M4sse/chromium.src,PeterWangIntel/chromium-crosswalk,dednal/chromium.src,Jonekee/chromium.src,mohamed--abdel-maksoud/chromium.src,Jonekee/chromium.src,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,Jonekee/chromium.src,ltilve/chromium,jaruba/chromium.src,Chilledheart/chromium,chuan9/chromium-crosswalk,Chilledheart/chromium,TheTypoMaster/chromium-crosswalk,chuan9/chromium-crosswalk,Pluto-tv/chromium-crosswalk,chuan9/chromium-crosswalk,krieger-od/nwjs_chromium.src,dednal/chromium.src,dednal/chromium.src,dushu1203/chromium.src,jaruba/chromium.src,ltilve/chromium,axinging/chromium-crosswalk,Just-D/chromium-1,krieger-od/nwjs_chromium.src,Chilledheart/chromium,hgl888/chromium-crosswalk,dushu1203/chromium.src,PeterWangIntel/chromium-crosswalk,ltilve/chromium,krieger-od/nwjs_chromium.src,Just-D/chromium-1,Jonekee/chromium.src,chuan9/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,dednal/chromium.src,Pluto-tv/chromium-crosswalk,Just-D/chromium-1,Just-D/chromium-1,krieger-od/nwjs_chromium.src,M4sse/chromium.src,hgl888/chromium-crosswalk,krieger-od/nwjs_chromium.src,M4sse/chromium.src,chuan9/chromium-crosswalk,Jonekee/chromium.src,markYoungH/chromium.src,axinging/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,hgl888/chromium-crosswalk,axinging/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,jaruba/chromium.src,krieger-od/nwjs_chromium.src,Chilledheart/chromium,fujunwei/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,dushu1203/chromium.src,Pluto-tv/chromium-crosswalk,hgl888/chromium-crosswalk,fujunwei/chromium-crosswalk,markYoungH/chromium.src,PeterWangIntel/chromium-crosswalk,axinging/chromium-crosswalk,dushu1203/chromium.src,mohamed--abdel-maksoud/chromium.src,M4sse/chromium.src,Fireblend/chromium-crosswalk,axinging/chromium-crosswalk,M4sse/chromium.src,dednal/chromium.src,PeterWangIntel/chromium-crosswalk,markYoungH/chromium.src