Fix generate_about_tracing_contents_unittest.GenerateAboutTracingContentsUnittTest
Fix generate_about_tracing_contents_unittest.GenerateAboutTracingContentsUnittTest

R=nduca@chromium.org

Review URL: https://codereview.appspot.com/223970043

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