Remove user-select: none on overlay so we can select --enable-skia-benchmarking
Remove user-select: none on overlay so we can select --enable-skia-benchmarking

BUG=231
R=nduca@chromium.org

Review URL: https://codereview.appspot.com/10038043
SummerLW/Perf-Insight-Report,zeptonaut/catapult,danbeam/catapult,sahiljain/catapult,sahiljain/catapult,vmpstr/trace-viewer,sahiljain/catapult,scottmcmaster/catapult,benschmaus/catapult,scottmcmaster/catapult,sahiljain/catapult,dstockwell/catapult,vmpstr/trace-viewer,benschmaus/catapult,SummerLW/Perf-Insight-Report,sahiljain/catapult,catapult-project/catapult,benschmaus/catapult,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult,benschmaus/catapult,0x90sled/catapult,modulexcite/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,0x90sled/catapult,danbeam/catapult,zeptonaut/catapult,catapult-project/catapult,catapult-project/catapult,SummerLW/Perf-Insight-Report,scottmcmaster/catapult,dstockwell/catapult,danbeam/catapult,0x90sled/catapult,dstockwell/catapult,zeptonaut/catapult,modulexcite/catapult,danbeam/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,sahiljain/catapult,catapult-project/catapult,dstockwell/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,modulexcite/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,catapult-project/catapult,benschmaus/catapult,vmpstr/trace-viewer,benschmaus/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult-csm