Use backward compatible object literal syntax in table builder
Use backward compatible object literal syntax in table builder

This tiny syntax modification ensures that Trace Viewer is compatible
with browsers not supporting ECMAScript 6.

BUG=
R=skyostil@chromium.org

Review URL: https://codereview.appspot.com/234680043

benschmaus/catapult,catapult-project/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,sahiljain/catapult,benschmaus/catapult,danbeam/catapult,0x90sled/catapult,danbeam/catapult,dstockwell/catapult,catapult-project/catapult-csm,danbeam/catapult,vmpstr/trace-viewer,sahiljain/catapult,scottmcmaster/catapult,catapult-project/catapult,benschmaus/catapult,benschmaus/catapult,catapult-project/catapult-csm,scottmcmaster/catapult,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,zeptonaut/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,scottmcmaster/catapult,catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult,SummerLW/Perf-Insight-Report,vmpstr/trace-viewer,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,dstockwell/catapult,sahiljain/catapult,dstockwell/catapult,0x90sled/catapult,zeptonaut/catapult,modulexcite/catapult,sahiljain/catapult,0x90sled/catapult,danbeam/catapult,vmpstr/trace-viewer,sahiljain/catapult,modulexcite/catapult,catapult-project/catapult-csm,sahiljain/catapult,benschmaus/catapult,zeptonaut/catapult,catapult-project/catapult-csm,catapult-project/catapult,dstockwell/catapult,modulexcite/catapult